高效液相色谱-质谱法测定猪组织中硝基咪唑类药物残留量

建立了一种高灵敏度和高选择性的检测猪组织中硝基咪唑类药物残留的高效液相色谱-大气压化学电离质谱(APCI)法,可同时进行猪组织中3种硝基咪唑类药物残留的确证分析.本方法检测猪肌肉、肝脏、肾脏和皮下组织中硝基咪唑类药物的检测限为0.5～1μg/kg;空白组织添加硝基咪唑类药物水平为0.5、1、2或4μg/kg时,测得回收率:肌肉为61.1%～85.4%,肝脏为62.3%～80.4%,肾脏为61.6%～82.0%,皮下组织为63.6%～84.1%.     

菌根性食用菌栽培研究进展

对目前菌根性食用菌栽培研究的进展进行了综述。重点介绍了菌根性食用菌与共生植物的相互作用,几种主要菌根性食用菌的培养条件、接种方法和栽培方法,以及种植园管理技术的研究现状。     

Activity of glutathione S-transferase toward some herbicides and its regulation by benoxacor in non-embryogenic callus and in vitro regenerated tissues of Zea mays

A procedure was developed to obtain non-embryogenic callus and regenerated lines from root segments of Zea mays grown in aseptic conditions. The activity of glutathione-S-transferases (GSTs), for non-embryogenic callus, was determined toward 1-chloro-2,4-dinitrobenzene (CDNB) and it was compared with that obtained for corn seedlings grown without hormones. For the callus masses, increases of specific activity toward CDNB and the kinetic parameter V_max were observed with respect to corn seedlings. The procedure permitted the regenerating of tissues from callus explants, therefore the GST(CDNB) activity and the effect of the safener benoxacor on its expression were investigated for the regenerated tissues grown in agarized substrate and in liquid medium. These explants showed a constitutive GST(CDNB) activity higher than corn seedlings and this activity was increased, for both tissues, in response to the presence of the safener benoxacor in the growing medium. The GST activity for the above tissues was also assayed toward benoxacor and terbuthylazine, metolachlor and fluorodifen herbicides. Measurable GST activity was found toward some of the above chemicals and it was found to be significantly enhanced in response to benoxacor treatment.     

Evaluation of a Bacillus stearothermophilus tube test as a screening tool for anticoccidial residues in poultry

A Bacillus stearothermophilus var. calidolactis C953 tube test was evaluated for its ability in detecting the residue of selected anticoccidial drugs in poultry, specically sulfamethazine, furazolidone, and amprolium. Various concentrations of each drug were injected into chicken liver and kidney tissues and these tissues were tested to determine the drug detection limits for each drug. The detection limit was defined as the drug concentration at which 95% of the test results were interpreted as positive. The limits of detection in liver tissue were 0.35 µg/ml for furazolidone, 0.70 µg/ml for sulfamethazine and 7.80 µg/ml for amprolium. In kidney tissues, they were 0.30 µg/ml for furazolidone, 0.54 µg/ml for sulfamethazine, and 7.6 µg/ml for amprolium. It was concluded that this tube test could be used to screen for the residue of these three drugs in poultry.     

氧氟沙星在肉鸡体内残留的研究

建立了氧氟沙星在肉鸡组织内残留的高效液相色谱分析法。采用荧光检测器，激发波长278nm，发射波长445nm。色谱柱为Hypersil BDS—C18，柱温40℃；以磷酸（三乙胺调pH至2．5）-乙腈（86：14）为流动相，流速1．0mL／min；进样量为20μL。氧氟沙星在肌肉、肝脏和肾脏中的平均回收率分别为96．3％、87．5％和76．4％，检测限为10ng／g，在10～1000ng／mL浓度范围内，氧氟沙星的峰面积与其浓度呈良好的线性相关，达到了氧氟沙星残留分析的要求。利用建立的方法对氧氟沙星在肉鸡体内的残留消除规律进行了研究，以1L水添加500mg的剂量，对120只肉鸡连续给药5d，对不同停药时间所取肌肉、肝脏和肾脏样品中的药物残留进行分析。结果表明，氧氟沙星在肉仔鸡组织中的残留消除速度较为缓慢，至休药23d时，仍可在肝脏和肾脏分别检出39和35μg/kg的氧氟沙星残留。在本实验的条件下，建议氧氟沙星临床休药期以25d为宜。     

Monoclonal antibodies putatively identifying porcine B cells

Comparison was made of the binding of 38 test and three standard monoclonal antibodies (mAbs) to B cells from various pig lymphoid tissues by flow cytometry (FCM) and immunohistochemistry. Some mAbs were also tested on B cells from foetal pig tissues. Twenty of the new mAbs bound, though to variable degrees, to porcine B cells but only three were given cluster assignations: C35 (#147) and BB6-11C9 (#167) were assigned to wCD21 and 2F6/8 (#057) was assigned to SWC7.     

浅析天津市专用型优质食用玉米的现状及发展对策

分析了影响天津市专用型食用玉米发展的品种混乱、重品种而忽视因种栽培、轻视投入、加工贮藏技术滞后等4个因素及天津市专用型食用玉米市场前景。为此提出加强引种和育种研究，重视专用型食用玉米栽培技术的研究，扩大宣传和政策扶持，开拓培育专用型食用玉米市场，建立种植、加工、销售一体化格局等5个对策。     

蜻蜓目的3种食用种类与营养价值

蜻蜓是分布广泛的昆虫 ,部分种类的稚虫可以食用。调查和研究成果表明 :在云南省的许多地方都有食用蜻蜓稚虫的习俗 ,常见的食用种类有红蜻、角突箭蜓、舟尾丝等 3种 ,其中含有蛋白质、脂肪、氨基酸、矿质元素等营养成分。它们的蛋白含量平均为 58.92 % ,脂肪含量平均为2 5.3 7% ,氨基酸含量平均为 4 6.0 3 % ,人体必需氨基酸含量平均为 16.4 1% ,占氨基酸总量的3 5.69% ,3种蜻蜓稚虫 K、Zn、Ca、Fe的平均含量分别为 2 960、12 5.4、2 616.6、796.2 mg· kg-1。由此可见 ,蜻蜓稚虫是营养丰富的食用昆虫资源     

次生阔叶林改建为食用菌原料林后的群落恢复和林分生长

选择12年生林相较好的天然次生阔叶林,通过择伐更新和皆伐人促更新2种经营方式定向培育食用菌原料林。研究发现,择伐经营的经济效益较高,且有利于群落的快速恢复,经过7a的封育,林分蓄积量已达到择伐前的水平。皆伐人促更新获得的食用菌材虽较择伐利用高出40%左右,但因经营强度过大,保留的幼树受损严重而不利于伐后林木的生长与恢复,封育期内蓄积增长量分别为择伐更新和对照未经营区的64 7%和73 41%。动态监测结果显示,采用择伐和皆伐人促更新措施后群落恢复较快。疏伐后因透光度的急剧增加,阳性和中性树种大量侵入,地面芽植物和1年生植物的比例增高。到第7a时,高位芽植物的比例已接近未经营区的状态,乔、灌、草各层的物种多样性指数高于未经营的天然阔叶林,物种均匀度则与其相近。研究还发现,2种更新经营方式对土壤养分的损失较小,经过7a的恢复,林地土壤肥力已基本达到原有天然林水平。