高比活度碳-14标记毒氟磷的合成与分析

以[14C]碳酸钡为放射性同位素原料,通过格氏反应、Curtius重排、亲核加成、硫代及关环等7步反应,制备了同位素碳-14标记的毒氟磷粗品,经反相高效液相色谱（RP-HPLC）纯化获得标记物纯品14C-毒氟磷（N-[2-（4-甲基苯并[2-14C]噻唑基）]-2-氨基-2-氟代苯基-O,O-二乙基甲基膦酸酯,38.3 mCi）。7步反应的化学收率/放化收率为10%。其结构经核磁共振氢谱、质谱和放射性高效液相色谱（HPLC-FSA）分析确认。放射性薄层成像分析（TLC-IIA）、高效液相色谱-液体闪烁测量联用分析（HPLC-LSC）、高效液相色谱-流动液体闪烁测量/二极管阵列检测器/质谱联用分析（HPLC-FSA/PDA/MS）和LSC分析表明,14C-毒氟磷的放化纯度和化学纯度均大于98%,比活度为58.0 mCi/mmol,可作为放射性示踪剂,用于毒氟磷的代谢和环境行为等研究。     

放射性同位素碳-14标记氯虫苯甲酰胺的合成与分析

以[14C]碳酸钡为放射性同位素原料,通过格氏反应、亲核取代、胺化和缩合等8步放化反应制备了2种放射性同位素碳-14标记的氯虫苯甲酰胺粗品,经反相高效液相色谱(RPHPLC)纯化获得标记物纯品14C-氯虫苯甲酰胺[3-溴-N-[4-氯-2-甲基-6-(甲氨基[羰基-14C]甲酰基)苯基]-1-(3-氯-2-吡啶基)-1H-吡唑-5-甲酰胺(2,55.6 mCi)和3-溴-N-[4-氯-2-甲基-6-(甲氨基甲酰基)苯基]-1-(3-氯-2-吡啶基)-1H-吡唑-5-[羰基-14C]甲酰胺(3,58.6 mCi)]。以[14C]碳酸钡计,两种标记物的总放化收率分别为32%和52%。其结构经核磁共振氢谱、质谱和在线放射性高效液相色谱(HPLC-FSA)分析确认。放射性薄层成像分析(TLC-IIA)、离线放射性高效液相色谱分析(HPLC-LSC)、在线放射性高效液相色谱-二极管阵列检测器/质谱联用(HPLCFSA/PDA/MS)和LSC分析表明,两种14C-氯虫苯甲酰胺的放化纯度分别为99.8%和99.6%,化学纯度分别为99.1%和98.4%,比活度分别为52.45 mCi/mmol和52.30 mCi/mmol。这2种标记物可作为放射性示踪剂,可满足氯虫苯甲酰胺在中国的登记代谢试验研究的需要。     

~(14)C-葡萄糖在椪柑果实粒化枯水过程中的转移和转化

碰柑贮藏中期,囊辦注射~(14)C-葡萄糖后,在枯水果和正常果的果皮和非标记囊辦均出现放射性活度,并以标记囊辦及其对应果皮为中心,向周围递减,这可能是物理扩散的结果。初枯果果皮放射性活度显著低于正常果,而其不溶物的放射性活度和呼吸强度与对照相比均无显著差异;~(14)C-葡萄糖在初枯果果皮之间或囊辦之间的扩散显著比正常果容易。这说明枯水的起因并非果肉营养物向果皮转移,而可能与衰老有关。在枯水发展过程中,全枯果果肉有24.65%的~(14)C-葡萄糖转化为不溶性物质,显著高于正常果的6.41%;中枯果和全枯果的呼吸强度分别为17.18ml/h·kg 和23.64ml/h·kg,显著高于正常果的11.03ml/h·kR。因此,我们认为椪柑在枯水过程中,果肉可溶性营养物消失的主要原因是转化为不溶性物质向果皮转移和呼吸消耗。     

高比活度碳-14标记氟噻草胺的合成与分析

为开展除草剂氟噻草胺在我国的登记代谢试验,本研究以4-氟[U-¹⁴C]苯胺为同位素原料,经还原胺化、缩合、取代、水解和醚化五步放化反应获得N-(4-氟[U-¹⁴C]苯基)-N-异丙基-2-((5-(三氟甲基)-1,3,4-噻二唑-2-基)氧基)乙酰胺(2,总活度201.65 MBq;比活度2 049.80 MBq·mmol^-1;化学纯度和放化纯度均大于98%,总放化收率39%);以[¹⁴C]硫氰酸钠为同位素原料,经加成、水解、环化、重氮化和醚化五步放化反应获得N-(4-氟苯基)-N-异丙基-2-((5-(三氟甲基)-1,3,4-[2-¹⁴C]噻二唑-2-基)氧基)乙酰胺(3,总活度287.86 MBq;比活度2 042.40 MBq·mmol^-1;化学纯度和放化纯度均大于98%,总放化收率14%)。两种标记物的结构经核磁共振氢谱(¹H NMR)和质谱(MS)分析确认,质量指标经高效液相色谱(HPLC-PDA)、放射性薄层成像分析(TLC-IIA)、在线放射性高效液相色谱(HPLC-FSA)和液体闪烁法(LSC)测定,均可作为放射性示踪剂。本研究结果为氟噻草胺的同位素示踪研究(包括该除草剂在我国的登记代谢试验)奠定了物质基础。     

麦棉套作系统生理学特性研究

在大田条件下利用同位素示踪技术对麦棉套作系统的生理学特性进行了研究。结果表明,麦棉套作系统的生长发育表现出两头强（小麦抽穗前长势强,棉花吐絮期贪青晚熟）,中间弱（共生期内小麦早衰、棉苗长势弱）的特点;小麦生育后期（抽穗后）特别是在灌浆后期群体根系活力明显降低,穗内３２Ｐ矿质分配比率减少,茎叶的代谢活力下降;套作棉花在蕾铃期群体根系活力降低,且根系活力高值期出现的时间后延１５～２５天,高值持续期明显缩短。生殖器官内３２Ｐ矿质分配比率,从蕾期一直到吐絮期也不同程度的相对降低。但麦棉套作经济效益比单作棉花增加１７８％以上,本文根据研究结果提出了栽培技术建议。     

SCINTIGRAPHIC EVALUATION OF THE THORACIC SPINE IN THE ASYMPTOMATIC RIDING HORSE

Scintigraphic evaluation of the spinous processes of the equine spine has been done by subjective evaluation of radiotracer uptake in clinically abnormal horses. To determine the range of variation in asymptomatic riding horses, 33 normal horses were examined. Two 60 degrees oblique views of the thoracic and lumbar spine were evaluated subjectively, and a semi quantitative method based on standardized regions of interest in each spinous process in T10-L3 was also applied. A ratio between each spinous process and a reference area (Rib 15 or 16) was calculated. The effects of two different color displays and a smoothing filter were assessed. The results of the subjective evaluation was compared to the calculated ratios, and the associations between age, gender, weight, height, use and increased radiotracer uptake, and ratios were analyzed. No significant association was found between age, gender, weight, height, use and increased radiotracer uptake, or ratio. One or more areas of increased radiotracer uptake between T13 and T18 were common in the asymptomatic riding horse, which may have implications for the interpretation of clinical patients. The blue, green and red color display had a higher sensitivity for detecting increased radiotracer uptake compared to the continuous grayscale. The smoothing filter used in this study had no effect on the detection of areas with increased radiotracer uptake. The association between the results of the subjective evaluation and the semi quantitative method was apparent when analyzed in T13-17. To evaluate if the semi quantitative method can replace the subjective evaluation, studies on clinically affected horses are necessary.