PCR-ELISA技术及其在生物医学领域中的应用

聚合酶链反应-酶联免疫吸附(PCR-ELISA)技术是利用PCR的高敏感性、核酸探针的特异性、酶标仪直接读取结果的客观性等优点创建的一项技术,自建立以来得到了广泛的关注。本文对这项技术做了基本介绍,并重点对近些年来其在生物医学领域中的应用进行综述。     

复配杀虫剂处理衣服对硬蜱的防护效果研究

目的 研究氯菊酯、ES-生物丙烯菊酯、乙酰甲胺磷、残杀威4种作用机制不同的杀虫剂复配处理衣服对蜱的防护效果。方法直接接触。结果 草原革蜱和青海血蜱分别接触被处理的衣服9min和5min．死亡率达100％，麻点璃眼蜱和血红扇头蜱接触15min，死亡率达100％。4种蜱接触被处理的衣服1min后，青海血蜱2h的死亡率达100％，其它3种蜱7h死亡率达100％。结论 该复配杀虫剂处理衣服对硬蜱有很好的防护效果。     

Dieldrin and heptachlor epoxide residues in fat from hogs foraging on corn stover in insecticidally treated fields

Summary Hogs pasturing on corn stover in insecticidally treated fields accumulated measurable residues of dieldrin and heptachlor epoxide. Hogs weighing between 40 and 60 pounds were placed on these treated fields for varying periods of time. Residues of heptachlor epoxide and dieldrin accumulated in the fat to levels of from 0.032 to 0.071 ppm. of heptachlor epoxide and from 0.080 to 0.141 ppm. of dieldrin. Removal of the animals to concrete slabs for further fattening for varying periods of time reduced but did not eliminate these residues.Journal paper No.4471, Purdue University Agriculture Experiment Station     

Determination of clomazone residues in soybean and soil by high performance liquid chromatography with DAD detection

A simple analysis method to detect clomazone residues in soybean and soil was developed using solid phase extraction coupled with high performance liquid chromatography with diode-array detection. The pesticide residues present in soybean and soil matrices were extracted with methanol–water and extracts purified with Florisil cartridges. The analytes from soybean and soil matrix were eluted with petroleum ether-acetic ether (10 mL, 95:5, v/v) and petroleum ether-acetic ether (2 mL, 95:5, v/v), respectively. The overall recovery of fortified soybean and soil at the levels of 0.01, 0.1 and 0.5 mg/kg ranged from 89.75% to 106.6%, and the coefficients of variation (CV) ranged from 1.68% to 4.93% (n = 3). The limit of quantification (LOQ) is 0.01 mg/kg. This method has been applied to the analysis of clomazone in real samples of soybean and soil. The dissipation of residue over the time in soil coincided with C = 1.189e^−0.0926t and the half-lives (T_1/2) was 7.48 days. The final residue in soybean was lower than 0.01 mg/kg at harvest time. Direct confirmation of the analyte in real samples was achieved by gas chromatography-mass spectrometry.     

Soil microorganisms in cotton fields sequentially treated with insecticides

A crop protection system consisting of sequential treatments by six insecticides--dimethoate, monocrotophos, deltamethrin, endosulfan, cypermethrin, and triazophos--at recommended dosages in cotton fields in Punjab, India was investigated for its effects on nontarget soil microorganisms and their activities. Successive applications of the insecticides caused only short-lived adverse effects on the soil microorganisms. None of the insecticides used had any adverse effects on soil fungi as reflected by their total numbers. Significant change in Azotobacter numbers were observed after dimethoate, triazophos, and endosulfan treatment in 1998 soil. An increase of up to 71% in actinomycetes numbers was observed after deltamethrin treatment in the treated fields in 1995. Few short-term changes in iron-reduction capacity were observed after endosulfan and cypermethrin treatments. No adverse effect was observed on the soil respiration during all the experimental periods. The amount of residues detected in soil ranged from 8.5 to 42.0 ng g(-1)dry wt. soil for organophosphorus insecticides and from nondetectable to 5.55 ng g (-1)dry wt. soil for synthetic pyrethroids. It ranged between 7.3 and 35.6 ng g(-1)dry wt. soil for endosulfan. On many occasions two or three insecticide residues were detected together; therefore, the effect observed on soil microorganisms and their activities was a multiresidue effect. In 1998, crop soil amounts of insecticide residues were generally more than those in 1995 and 1996. Persistence and dissipation patterns in soils with a history of exposure to the insecticides compared to the non-history soils were similar.     

Changes in isoflavone profiles of soybean treated with gamma irradiation

Soybean is an important Brazilian agricultural commodity that contains a high concentration of isoflavones. Many studies showed that isoflavones are active in the prevention of many human diseases. However, the correct processing techniques used to prepare the soy foodstuffs are important to maintain the active forms. The objective of this study was to evaluate the effect of gamma irradiation on the isoflavone contents of the defatted soybean flour when compared with soybean molasses, a derivative from the soybean food production. After extracting phenolic compounds with methanol aqueous solution (80%), isoflavones were detected by reverse-phase high-performance liquid chromatography/diode-array detector. The radiation doses of 2 and 5 kGy presented a small effect on the isoflavones content of defatted soy flour. Samples irradiated at 50 kGy showed lower isoflavone contents. The observed reduction in the concentration of isoflavones-daidzein, glycitein and genistein-induced by gamma radiation in soy molasses was not significant in defatted soy flour, thus suggesting that isoflavones in defatted soy flour were not eliminated by gamma radiation at rates up to 50 kGy.     

复合电磁场处理污水试验及效果评价

目的：探讨污水经复合电磁场处理后能否回收利用。方法：以污水中水质较为恶劣的医院污水为对象，用复合电磁场对其进行处理，检测处理前后各项水质指标，并把处理后水与生活日用水水质标准进行比较。结果：处理后水的总大肠菌群为0cfu/L，各理化指标除化学耗氧量（COD）外，均达到生活杂用水水质标准的要求。结论：污水经一定的预处理，再用复合电磁场系统进行净化后，可以达到回收利用的水质要求。     

Residue analyses and biotests in rice fields of East Java treated with thiodan

Summary Endosulfan residues declined rapidly — within three to five days — in the water of THIODAN treated test rice fields near Pandaan (East Java). Terminal residues in the water amounted to 0.0005–0.0008 ppm. These residues were due to the constant large scale application in this area. It was noted, that fish are able to tolerate short time exposure of endosulfan concentrations 4 times the LC₁₀₀. In the mud of submerged as well as dried rice fields, only very low residues (1.9 ppm maximum) were found. The increasing sulfate equivalent in the total residue points to decomposition of the chemical.The biocoenosis, which was impaired at the beginning of the test, reappeared after completion of the test.