氰霜唑及其代谢物4-氯-5-(4-甲苯基)-1H-咪唑-2-腈在苦瓜中的残留消解动态及膳食安全性评价

[目的]研究旨在优化苦瓜中氰霜唑(Cyazofamid)及其代谢物CCIM的QuEChERS-液相色谱-串联质谱残留分析方法;同时结合苦瓜的田间残留消解动态试验,对膳食摄入风险进行评价。[方法]苦瓜样品采用含1%乙酸的乙腈溶液提取,LC-MS/MS进行检测,通过基质匹配标准溶液外标法定量。通过在黑龙江、河北、河南、重庆、浙江和广东6地进行了100 g/L氰霜唑悬浮剂在苦瓜上残留的田间试验,研究了氰霜唑在苦瓜中的消解动态,对苦瓜中氰霜唑可能产生的膳食摄入风险安全进行评价。[结果]试验结果表明：1)氰霜唑在0.005-1.0 mg/L、CCIM在0.001-1.0 mg/L质量浓度范围内线性关系良好,相关系数均大于0.9987;在0.010、0.10、0.50 mg/kg 3个浓度下,苦瓜中氰霜唑及CCIM的回收率为80.0%～100.0%,相对标准偏差(RSD)为0.05%～12.1%。检出限(LOD)为0.364-0.654 μg/kg,方法定量限(LOQ)为添加的最低浓度0.010 mg/kg。2)田间试验结果表明：氰霜唑在苦瓜中消解符合一级反应动力学方程,半衰期为3.0～4.9 d,属易降解农药;使用100 g/L氰霜唑悬浮剂,施药剂量105-157.5 g a.i./hm2,分别施药2、3次,苦瓜中氰霜唑总的最终残留量最大值为6.54 mg/kg。3)膳食摄入风险评估结果表明：氰霜唑的风险概率为每人每日摄入总量的1.0%。[结论]在苦瓜生长期间按照推荐剂量合理使用氰霜唑对消费者的膳食健康风险极低,对消费者健康是安全的。     

适应山地的两轮农耕机优化设计

目的对农耕机进行优化设计,减轻农民体力负担,提高农耕效率,减少安全隐患,向其它农业设备中推广。方法通过解析目前农耕机的缺陷,并以比阳产品设计公司的实际项目为例,找到目前农耕机设计中急需解决的问题,提出优化设计方案。结论通过对新机架结构中轮系与扶手的优化,使机架灵活移动;通过轻质耐磨材料的应用,减轻机身质量;通过变速技术的应用,解决农耕机速度控制的问题来提高生产安全与效率。     

呋喃唑酮代谢物抗体的制备与筛查

利用呋喃唑酮的4种代谢物合成免疫原以及包被原,用4种免疫原各免疫两只新西兰大白兔,得到8份抗血清,再纯化抗血清。采用间接ELISA方法,筛选出OD值明显高于阴性样本的血清用于以后的实验,同时对抗体的效价进行测定。实验检测结果表明,当用包被原A和包被原B包被酶标板时,7号和8号抗血清对该包被抗原有很好的亲和性,呋喃唑酮代谢物衍生物对抗体有很好的抑制。通过效价检测,7号和8号抗血清均具有高效价、高特异性的特点,其中8号抗血清的效价更高,亲和力更强。再通过进一步对两种包被原和两份抗血清进行筛查,选择B包被原和8号兔子的抗体清用于ELISA法的建立。     

城市农耕景观规划理论研究

近年来由于自然灾害和人为因素的影响,使得食品安全危机不断地出现在我们身边,人们对于健康绿色生活的愿望越来越迫切。文章通过规划手段,对现实中发生的一些关于人们的生活、饮食等相关问题从城市园林景观角度进行规划分析,通过利用城市农耕景观和城市园林景观相互结合的理论方法,提出了城市农耕景观规划的理论框架,进而给人们创造一个能够参与到环境营造和食品生产等一系列的活动的机会。文章提出了城市农耕景观的垂直空间规划、地域空间规划、水平季节规划和管理对策等,对城市景观规划研究领域起到一定的借鉴作用,推动了城市农耕景观的发展,使城市面貌更完善,食品更安全,进而打造我们的美丽中国。     

UPLC-MS/MS法同时检测大鼠体内7–乙基–14–氨基喜树碱及其代谢产物

7–乙基–14–氨基喜树碱（EAC）是具有良好抗肿瘤活性的新型喜树碱衍生物,为测定静脉注射EAC后原形化合物及其酰胺型代谢产物（EAC-M）在体内的浓度,揭示体内动力学性质,现研究建立了同时定量测定SD大鼠血浆中EAC和EAC-M的UPLC-MS/MS方法。以7–乙基–14–硝基喜树碱（ENC）、吉咪替康（CMT）为内标,血浆样品加入内标溶液和乙腈沉淀蛋白后,以Phenyl-Hexyl柱（2.1mm$times$50mm,1.8μm）为分离柱,5mmol/L醋酸铵水溶液（含0.1%甲酸）-乙腈为流动相梯度洗脱,流速0.5mL/min。洗脱物经电喷雾离子源（ESI）正离子化,在三重四级杆质谱仪上以多反应监测模式（MRM）测定EAC（m/z392→291）和EAC-M（392→290）。方法学研究结果显示,内源性物质不干扰待测物和内标的测定。在0.500～250ng/mL范围内,EAC和EAC-M的浓度与响应值的线性关系良好,定量下限均为0.500ng/mL。方法的日内、日间精密度（RSD）≤7.6%,准确度（RE）为–4.2%～5.9%。提取回收率为84.4%～98.7%,基质效应为94.8%～104%。高于定量上限浓度的样品,用空白血浆稀释6倍至线性范围,测得的精密度（RSD）为1.8%,准确度（RE）为–10%～–3.0%。样品经设定的稳定性考察条件后,测得的准确度（RE）为–8.6%～11%,RSD<7.2%。药代动力学结果显示,静脉注射后EAC在大鼠体内的清除速率中等,组织分布高。给药后EAC-M在血浆中迅速检出,暴露量约相当于EAC的5%。连续给药5d,EAC和EAC-M在大鼠体内无明显蓄积。所建立的方法简便、灵敏、选择性强,适用于SD大鼠血浆中EAC及代谢产物EAC-M的测定和药代动力学研究。     

培养条件和果汁种类对脂环酸芽孢杆菌生长的影响

脂环酸芽孢杆菌是造成巴氏灭菌果汁腐败的重要细菌之一。鉴于目前脂环酸芽孢杆菌的培养方法尚未统一且污染特征不明确,本研究考察了pH、7种培养基和9种果汁对其生长的影响,同时采用固相微萃取(SPME)和气相色谱(GC)-质谱(MS)技术检测了该菌的主要代谢产物愈创木酚和2,6-二溴苯酚在果汁中的释放情况。结果表明,脂环酸芽孢杆菌在pH4.0时生长情况最好,pH2.5时生长较差,pH6.0~7.0时最差。AAM培养基和BAT培养基较其他5种培养基(YSG培养基、K氏培养基、SK培养基、PDB培养基和营养肉汤培养基)更适合用来培养脂环酸芽孢杆菌。脂环酸芽孢杆菌接种到9种果汁中后生长差异明显,在葡萄汁和橙汁中生长情况最好,细菌数量分别为1.5×10⁴ CFU/mL和8.5×10³ CFU/mL;在菠萝汁和西柚汁中生长缓慢,细菌数量分别为4.4×10² CFU/mL和1.9×10² CFU/mL。此外,9种果汁接种脂环酸芽孢杆菌后均未检测出2,6-二溴苯酚;但是,除葡萄汁外的8种果汁均检测出愈创木酚,浓度在8.6~23.9 μg/L之间。     

QuEChERS结合高效液相色谱-串联质谱同时测定荔枝龙眼中3种农药及代谢物残留

建立一种QuEChERS前处理方法结合高效液相色谱-串联质谱（high performance liquid chromatography-tandem mass spectrometry,HPLC-MS/MS）技术同时检测荔枝龙眼基质中苯醚甲环唑、氯虫苯甲酰胺、溴氰虫酰胺及代谢物J9Z38残留量的分析方法。荔枝龙眼基质样品采用乙腈作为提取溶剂,利用50 mg十八烷基键合硅胶（C18）、50 mg N-丙基乙二胺（PSA）和10 mg纳米氧化锆（Nano-ZrO2）3种吸附剂联合净化,用75 mm InfinityLab Poroshell 120 SB-C18色谱柱进行分离,并以0.1%（体积分数）甲酸水溶液-乙腈为流动相进行梯度洗脱,多反应离子监测模式（MRM）扫描,以基质匹配标准溶液进行定量分析。结果显示：4种目标化合物在1~100 μg/kg质量浓度范围内线性相关系数为0.9896~0.9999,定量限（LOQ）为0.10~10 μg/kg。荔枝龙眼中4种目标分析物的加标回收率为82.48%~99.17%,日内和日间相对标准偏差分别为4.11%~7.77%、6.10%~13.27%。本方法具有易于操作、简便快速和灵敏度高等优势,可应用于荔枝龙眼实际样品中苯醚甲环唑、氯虫苯甲酰胺、溴氰虫酰胺及代谢物J9Z38残留的同时检测分析。     

Compendium on Food Crop Plants as a Platform for Pharmaceutical Protein Production

Tremendous advances in crop biotechnology related to the availability of molecular tools and methods developed for transformation and regeneration of specific plant species have been observed. As a consequence, the interest in plant molecular farming aimed at producing the desired therapeutic proteins has significantly increased. Since the middle of the 1980s, recombinant pharmaceuticals have transformed the treatment of many serious diseases and nowadays are used in all branches of medicine. The available systems of the synthesis include wild-type or modified mammalian cells, plants or plant cell cultures, insects, yeast, fungi, or bacteria. Undeniable benefits such as well-characterised breeding conditions, safety, and relatively low costs of production make plants an attractive yet competitive platform for biopharmaceutical production. Some of the vegetable plants that have edible tubers, fruits, leaves, or seeds may be desirable as inexpensive bioreactors because these organs can provide edible vaccines and thus omit the purification step of the final product. Some crucial facts in the development of plant-made pharmaceuticals are presented here in brief. Although crop systems do not require more strictly dedicated optimization of methodologies at any stages of the of biopharmaceutical production process, here we recall the complete framework of such a project, along with theoretical background. Thus, a brief review of the advantages and disadvantages of different systems, the principles for the selection of cis elements for the expression cassettes, and available methods of plant transformation, through to the protein recovery and purification stage, are all presented here. We also outline the achievements in the production of biopharmaceuticals in economically important crop plants and provide examples of their clinical trials and commercialization.     

Spatio-temporal patterns of birch regrowth in a Western Norwegian treeline ecotone

The study investigates spatio-temporal patterns of birch regrowth in a mountain valley in which intensive livestock grazing was formerly practised. Vegetation changes were identified through analysis of three sets of aerial photographs. The results of GIS analyses, one-way ANOVA and PCA showed that regrowth patterns are complex. In the early phase of succession, grazing history has a strong impact on where new forest establishes, both at a distance from the seasonal farmsteads where grazing intensity prior to abandonment was highest, and close to previously existing forest. Sprouting is most likely to be the dominating regeneration strategy in this early phase. In a later phase of succession, the impact of grazing history on forest distribution patterns decreases, as exemplified by the increasing distance from existing forest. The largest amounts of birch forest then establish in warm locations with moderate moisture. Protection against wind appears to be important for birch establishment.     

Evaluation of the Impact of Ruminant Trans Fatty Acids on Human Health: Important Aspects to Consider

The definition and evaluation of trans fatty acids (TFA) with regard to foodstuffs and health hazard are not consistent. Based on the current situation, the term should be restricted only to TFA with isolated double bonds in trans-configuration. Conjugated linoleic acids (CLA) should be separately assessed. Ideally, the origin of the consumed fat should be declared, i.e., ruminant TFA (R-TFA) and industrial TFA (non-ruminant; I-TFA). In ruminant fat, more than 50% of R-TFA consists of vaccenic acid (C18:1 t11). In addition, natural CLA, i.e., c9,t11 CLA is also present. Both are elevated in products from organic farming. In contrast to elaidic acid (t9) and t10, which occur mainly in partially hydrogenated industrial fat, t11 is partially metabolized into c9,t11 CLA via Δ9-desaturation. This is the major metabolic criterion used to differentiate between t11 and other trans C18:1. t11 indicates health beneficial effects in several studies. Moreover, CLA in milk fat is associated with the prevention of allergy and asthma. An analysis of the few studies relating to R-TFA alone makes clear that no convincing adverse physiological effect can be attributed to R-TFA. Only extremely high R-TFA intakes cause negative change in blood lipids. In conclusion, in most European countries, the intake of R-TFA is assessed as being low to moderate. Restriction of R-TFA would unjustifiably represent a disadvantage for organic farming of milk.