本研究首先建立并验证了一种中兽药的提取方法，该方法能够提取中兽药产品中可能存在的克伦特罗、莱克多巴胺和沙丁胺醇等三种β-受体激动剂及其结构类似的物质。其次，采用该方法对105种批准在动物养殖中使用的中草药进行提取和浓缩，PBS复溶解后采用CGIA筛查存在阳性反应的中草药，出现阳性反应的样品随后经LC-MS/MS（液相色谱-串联质谱法）检测。在动物实验中，将105种中草药分别饲喂三元猪后，接取尿液进行CGIA检测，将有阳性反应的尿液样品进行LC-MS/MS检测。采用乙醇和乙腈（1:9，v/v）为溶剂，对中草药的提取效果良好，在105种受测的中草药的提取物中，青皮、陈皮、木瓜、厚朴和红景天等5种中草药的提取物出现CGIA阳性反应，其他中草药均显阴性反应。105种中草药分别饲喂猪后，喂过青皮和陈皮的猪只尿液出现CGIA检测阳性反应，其他中草药均显阴性反应，在随后的LC-MS/MS检测中喂过青皮和陈皮的猪只尿液未检出克伦特罗、莱克多巴胺或沙丁胺醇。在体外实验中，陈皮、青皮、木瓜、厚朴和红景天能引起克伦特罗、莱克多巴胺和沙丁胺醇CGIA检测阳性现象，该现象属于假阳性；三元猪被超剂量饲喂陈皮或青皮后，猪尿中莱克多巴胺的CGIA检测可出现假阳性。本研究首次提出了中草药的应用可能与临床CGIA检测β-受体激动剂出现假阳性的现象存在一定的关联性，提醒养猪从业者规范中草药添加剂的使用。发现引起猪尿假阳性的青皮和陈皮中存在有一种相同的化学成分——辛弗林，猪尿中存在相对浓度较低的辛弗林可引起莱克多巴胺的CGIA检测呈阳性反应。

Apple replant disease (ARD) causes the inhibition of root system development, stunts tree growth and so on. To further investigate the effects of ARD on apple fruits, a 25-year-old apple orchard was remediated to establish a replant orchard between November 2008 and March 2009. A rotational cropping orchard was established on an adjacent wheat field. The cultivar and rootstock-scion combination used in the newly established orchards was Royal Gala/M26/Malus hupehensis Rehd. Ripe fruits were collected in mid-August 2011 and mid-August 2012, meanwhile, the following indices were measured: yield per plant; fruit weight; the fruit shape index; the contents of anthocyanin, carotenoid and chlorophyll; the soluble sugar content in the flesh; titratable acid; the sugar-acid ratio; firmness; and aroma components; apple plant ground diameter, plant height increment and the total length of the current-year shoots. The results showed that compared to rotational cropping, continuous cropping yielded statistically significant reductions in fruit weight and yield per plant of 39.8 and 76.5%, respectively. However, there were no changes in the fruit shape index. The anthocyanin and carotenoid contents decreased by 81.7 and 37.7%, respectively, while the chlorophyll content increased by 251.0%. All of these differences in content were statistically significant. The soluble sugar levels and sugar-acid ratio decreased by 25.4 and 60.9%, respectively, but the titratable acid levels and fruit firmness increased by 90.9 and 42.8%, respectively. Ten of the most important esters contributing to the apple aroma were analyzed, and the following changes were observed: hexyl acetate, butyl acetate, hexyl butyrate, acetate-2-methyl butyl, 2-methyl-hexyl butyrate, amyl acetate, butyl butyrate, 2-methyl-butyl butyrate, hexyl propionate and hexyl hexanoate decreased by 25.5, 78.4, 89.1, 55.5, 79.5, 77.2, 86.8, 69.9, 61.2, and 68.1%, respectively. The contents of three other aroma components, (E)-2-hexenal, hexanal and 1-hexanol, significantly increased. Eight characteristic aroma components were found in the rotational cropping fruits: hexyl acetate, butyl acetate, acetate-2-methyl butyl, 2-methyl-hexyl butyrate, amyl acetate, 2-methyl- butyl butyrate, hexyl acetate and hexyl propionate. There were four characteristic ester components (hexyl acetate, butyl acetate, acetate-2-methyl butyl, 2-methyl-hexyl butyrate) and two characteristic aldehyde aroma components ((E)-2-hexenal and hexanal) in the continuous cropping fruits. Compared with the rotational cropping fruits, four characteristic ester components were declined and two characteristic aldehyde aroma components were increased. Compared with the control, replanted apple plant ground diameter, plant height increment and the total length of the current-year shoots were reduced by 27.6, 40.6 and 72.2%, respectively.

The pharmacokinetics of quinocetone and its major metabolites in healthy swine was investigated in this paper.Quinocetone was administered to 8 healthy cross-bread swine intravenously and orally at a dosage of 4 and 40 mg kg-1body weight respectively in a randomized crossover design test with two-week washout period. A sensitive highperformanceliquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method was developed for thedetermination of quinocetone and its metabolite 1-desoxyquinocetone in plasma. Plasma concentration versus timeprofiles of quinocetone and its metabolite 1-desoxyquinocetone were analyzed by non-compartmental analysis usingWinnonlin 5.2 software. Mean maximum concentrations (Cmax) for quinocetone was found to be (0.56±0.13) μg mL-1 at 2.92 h,after oral administration of quinocetone. Mean maximum concentrations (Cmax) for 1-desoxyquinocetone after intravenousor oral administration of quinocetone were (0.0095±0.0012) μg mL-1 at 0.083 h and (0.0067±0.0053) μg mL-1 at 3.08 h. Theapparent elimination half-lives (T1/2) for quinocetone and its metabolite 1-desoxyquinocetone were (2.24±0.24) and(5.23±0.56) h after intravenous administration of quinocetone and (2.91±0.29) and (11.85±2.89) h after oral administrationof quinocetone, respectively. Mean areas under the plasma concentration-time curve (AUC0- ) for quinocetone and 1-desoxyquinocetone were (2.02±0.15) and (0.2±0.002) μg h mL-1 respectively after intravenous administration of quinocetone,and (3.5±0.79) and (0.053±0.03) μg h mL-1 after oral administration of quinocetone, respectively. Quinocetone was rapidlyabsorbed and metabolized in swine after oral and intravenous administration. The plasma concentration-time curve(AUC0- ) of 1-desoxyquinocetone were much smaller than those of quinocetone, while the elimination half-lives (T1/2) weremuch longer than those of quinocetone after intravenously (i.v.) or oral administration.