兽药残留检测中磺胺嘧啶ELISA试剂盒的研制

以合成的耦联抗原BSA-磺胺嘧啶和磺胺嘧啶(SD)的单克隆抗体为材料,建立了SD间接竞争ELISA的方法。方法的检测灵敏度为0.213 ng/m L,线性检测范围为1.84~57.41 ng/m L,除与磺胺二甲嘧啶反应率超过10%外,与其他磺胺类药物交叉反应率均低于1.5%,4℃放置180 d没有明显的变化。采用猪尿、牛奶、猪肉3类样本进行的添加回收实验,批内CV均小与10%,批间CV小于15%,平均添加回收率介于75%~90%。因此,组建的试剂盒可以满足动物饲养检测SD的要求。     

牛血清蛋白酶联免疫检测试剂盒的研制及验证

为研制酶联免疫试剂盒以检测病毒性疫苗中残余牛血清蛋白(BSP)含量,制备高效价高纯度的兔抗BSP多克隆抗体作为包被抗体和酶标抗体,建立了ELISA双抗体夹心法并组建试剂盒,通过标准剂量曲线可对样品中所含BSP、BSA及B-IgG进行定量,经验证该方法标准曲线线性范围内r≥0.98,对BSP的检测限量为3ng/ml;分别检测5、10、20ng/ml含量的BSP时,试验内(n=12)和试验间(n=3)测定的变异系数在3.71%到7.29%之间,回收率在93.4%~106.3%,未见该方法与人血清白蛋白、卵清蛋白以及疫苗复合保护剂之间有交叉反应。该法敏感度高,准确性、重复性和稳定性好,可用于疫苗牛血清残余蛋白的质量控制。     

牛血清蛋白酶联免疫试剂盒性能的验证

为了全面验证研制的牛血清蛋白(BSP)酶联免疫试剂盒的性能,由3个部门6人协作进行了验证。结果表明,,6人进行的18次试验全部满足BSP-ELISA试剂盒的质控标准,达标率100%;6名实验人员对3、4、5、10、20ng/ml浓度的BSP标准品进行测定,结果变异系数在1.96%~6.24%之间,精密度较好;回收率在94.8%~98.7%之间,准确度理想,测量限量为3ng/ml。该试剂盒与人血白蛋白、卵清蛋白等均无交叉反应,对BSA、B-IgG特异性蛋白的检测回收率为101.2%和94.7%;与牛血清白蛋白试剂盒对比测定11种疫苗总计108批,符合率为96.3%,针对不同疫苗,BSP残余量约为BSA的1.12~3.13倍,验证结果表明,该试剂盒可检测疫苗中BSP而不仅是BSA,能更全面客观地反映疫苗中牛血清的真实情况,有利于疫苗生产的严格质量监控。     

应用ELISA和ELFA定量检测牛奶中葡萄球菌肠毒素A方法的建立

探讨了Tecra SEs SET(ELISA法)和Vidas SET2(ELFA法)两种葡萄球菌肠毒素定性检测试剂盒用于定量检测牛奶中葡萄球菌肠毒素A(SEA)的可行性。根据GB/T27404-2008《实验室质量控制规范食品理化检测》的要求,对两种方法应用于定量检测时的检出限、校正曲线范围、相关系数和加标回收率指标进行了分析比较。实验结果显示,Tecra SEs SET对牛奶中SEA的检出限为0.79 ng/mL,校正曲线范围为0.79~10 ng/mL,相关系数r=0.997,SEA加标浓度为0.80、2.5和10 ng/mL时的回收率分别为110%、81%和100%。Vidas SET2的检出限为0.09 ng/mL,校正曲线范围为0.09~1.0 ng/mL,相关系数r=0.998,SEA加标浓度为0.1、0.25和1.0 ng/mL时的回收率分别为90%、95%和104%。上述结果结合对阳性样品的检测表明:这两种定性检测试剂盒能满足牛奶中SEA定量检测的要求。     

毛豆中腈菌唑残留量的气相色谱法测定

采用气相色谱法定量分析毛豆上腈菌唑的微量残留量。样品经乙腈提取,液液分配,中性氧化铝柱层析净化后,以气相色谱电子俘获检测器法(GC-ECD)测定,DB-1701毛细管柱、氮气为载气,柱温150℃20℃/min 260℃(10 min),气化室温度240℃,检测器温度300℃,外标法定量。该方法快速、准确,在0.05~2.00 mg/L范围内线性相关系数r²=0.9998,平均回收率91.1%~99.0%,变异系数1.22%~2.94%,最小检测量1.0×10^-12 g,最低检出浓度5.0×10^-4 mg/kg。     

电热蒸发-催化热解-原子吸收法直接测定茶叶中镉

重金属镉（Cd）一直是茶叶产品质量安全关注的重点。本研究基于电热蒸发-催化热解-原子吸收光谱仪（SS-ETV-AAS）,使用镍材质样品舟,在300 mL/min空气条件下,350 ℃干燥20 s,350~725 ℃灰化55 s;引入300 mL/min氢气与空气反应形成氮氢混合气氛,在725~800 ℃（50 s）下完成Cd的蒸发;之后,在高岭土填料催化热解炉800 ℃和准直管700 ℃条件下,氮氢火焰原子吸收测定镉的含量。方法检出限（LOD）为0.3 ng/g、定量限（LOQ）为1.0 ng/g,R2>0.998,多次测定的相对标准偏差（RSD）为1.8%~8.6%,多种茶叶样品中Cd的测定值与微波消解石墨炉原子吸收光谱法（GFAAS）无显著性差异（P>0.05）,Cd的回收率在92%~107%之间。试验结果表明,该方法灵敏度高、稳定性好、简单高效,且无需消解处理,样品分析时间仅为3min,适用于茶叶中Cd的快速检测。     

霍乱疫苗中残余霍乱毒素检测方法的建立及验证

采用间接酶联免疫法,即用神经节苷脂包被,加入待检样品,再加入兔抗霍乱毒素B亚单位抗体,用标准样品的吸光值(A值)对标准样品的浓度绘制4-参数拟合曲线,根据标准曲线计算出待测样品中的CT浓度。结果显示,在浓度范围(0.6～16)ng/ml之间,CT标准浓度和检测浓度成线性关系,r2=0.9986。精确度在浓度范围(0.6～16)ng/ml,CT的平均回收率在96.24%～114.44%之间。精密度:批内变异CV%≤12.98%,批间变异CV%≤18.48%。特异性CT浓度在10ng/ml时,平均回收率为102.6%;CT浓度在5ng/ml时,平均回收率为111.17%;CT浓度在2.5ng/ml时,平均回收率为123.83%。实验表明该方法可检测霍乱疫苗原液中CT的含量。     

毛细管气相色谱法测定甲磺酸伊马替尼中残留有机溶剂

目的：建立可同时测定甲磺酸伊马替尼原料药中甲醇、乙醇和N''N - 二甲基甲酰胺（DMF）等3 种残留有机溶剂的毛细管气相色谱法。方法：采用WondaCAP WAX 毛细管柱为色谱柱，程序升温，N2 为载气，载气流速为4.0 mL ? min-1，氢火焰离子化检测器，检测器温度为250 ℃，进样口温度为200 ℃，进样量为1.0 μL。以正丁醇为内标，通过内标法计算样品中3 种有机溶剂残留量。结果：甲醇、乙醇和DMF 在所建立的色谱条件下均能完全分离，分别在2.94~44.11、4.91~73.68 和0.084~12.60 mg ? L-1 的质量浓度范围内线性关系良好（r =0.9940~0.9985），进样精密度（RSD）均小于5.0%（n =6），平均回收率为104.8%~105.8%（RSD<5.0%，n =9），定量限分别为0.20、0.33 和0.08 ng（信噪比为10 ∶ 1），检测限分别为0.05、0.11 和0.02 ng（信噪比为3 ∶ 1）。样品中未检出甲醇和DMF，乙醇含量低于有关限度规定。结论：该方法简便、准确、灵敏、重复性好，可用于甲磺酸伊马替尼原料药中残留有机溶剂的检测。     

LC-MS/MS测定荷瘤裸鼠血浆中和厚朴酚脂质体浓度及其药代动力学研究

目的:建立测定荷瘤裸鼠血浆中和厚朴酚脂质体的高效液相色谱-质谱联用(LC-MS/MS)法,并进行荷瘤裸鼠体内药代动力学研究。方法:采用YMC C18(100 mm×2.1 mm,1.7μm)色谱柱,流动相B为0.025%氨水乙腈,A为0.025%氨水,在线脱气,流速0.8 m L/min。梯度洗脱:0~2 min,B相85%~85%;2~4 min,B相85%~10%;4~6 min,B相10%~85%;6~8 min,B相85%~85%,柱温40℃。进样量10μL。质谱条件:离子源电喷雾电离源(ESI),负离子电离模式,扫描方式多级反应监测(MRM),监测离子对m/z和厚朴酚(265.0→223.0)和内标(253.0→225.0)。结果:血浆中无干扰测定的内源性物质,每个样品的分析时间为8 min;和厚朴酚在0.500~1000 ng/m L呈良好的线性关系,定量下限为0.500 ng/m L,日内、日间精密度RSD均小于15%,低、中、高3种浓度的提取回收率64.71%。稳定性实验中,在各种贮存条件下血浆中和厚朴酚均较稳定。结论:本方法操作简便,特异性强,灵敏度高,可用于和厚朴酚脂质体的药代动力学研究,以期为临床应用提供参考。     

破伤风类毒素抗体酶联双抗原夹心法定量检测试剂的研制及评价

研制破伤风类毒素抗体酶联双抗原夹心法定量检测试剂,用于破伤风免疫血浆抗体效价检测。以精制破伤风类毒素经Sephacryl S-300柱层析纯化后作为包被抗原,用辣根过氧化物酶以改良过碘酸钠法标记精制破伤风类毒素作为酶标记抗原,以破伤风人免疫球蛋白国家标准品采用小鼠中和试验法标定试剂盒定量标准品,制备双抗原夹心法定量检测试剂;进行试剂盒检测范围、特异性、重复性、精密度及稳定性考核,并与小鼠中和试验法、琼脂双扩散法及国外破伤风类毒素抗体酶联试剂盒进行比较。结果显示,试剂盒的检测范围为10~150mIU/ml,灵敏度为10mIU/ml,线性好(r>0.996),板内孔间变异度小(CV<8%),特异性强(100%),重复性好(CV<13%),于37℃放置6天测定结果无明显差异,与小鼠中和试验法、英国Biding Site酶联试剂有良好的一致性。试验证明所研制的试剂盒适用于破伤风免疫血浆中的破伤风抗体效价定量检测。     

Curcuminoids as inhibitors of thioredoxin reductase: A receptor based pharmacophore study with distance mapping of the active site

Curcumin is the yellow pigment of turmeric that interacts irreversibly forming an adduct with thioredoxin reductase (TrxR), an enzyme responsible for redox control of cell and defence against oxidative stress. Docking at both the active sites of TrxR was performed to compare the potency of three naturally occurring curcuminoids, namely curcumin, demethoxy curcumin and bis-demethoxy curcumin. Results show that active sites of TrxR occur at the junction of E and F chains. Volume and area of both cavities is predicted. It has been concluded by distance mapping of the most active conformations that Se atom of catalytic residue SeCYS498, is at a distance of 3.56 from C13 of demethoxy curcumin at the E chain active site, whereas C13 carbon atom forms adduct with Se atom of SeCys 498. We report that at least one methoxy group in curcuminoids is necessary for interation with catalytic residues of thioredoxin. Pharmacophore of both active sites of the TrxR receptor for curcumin and demethoxy curcumin molecules has been drawn and proposed for design and synthesis of most probable potent antiproliferative synthetic drugs.     

A Unique Protease Cleavage Site Predicted in the Spike Protein of the Novel Pneumonia Coronavirus (2019-nCoV) Potentially Related to Viral Transmissibility

正Dear Editor,In December 2019, a novel human coronavirus caused an epidemic of severe pneumonia(Coronavirus Disease 2019,COVID-19) in Wuhan, Hubei, China(Wu et al. 2020; Zhu et al. 2020). So far, this virus has spread to all areas of China and even to other countries. The epidemic has caused 67,102 confirmed infections with 1526 fatal cases     

Comparative morphology of the carpel in the Liliaceae: Hewardieae, Petrosavieae, and Tricyrteae

The young pistils in the melanthioid tribes, Hewardieae, Petrosavieae and Tricyrteae, are uniformly tricarpellate and syncarpous. They lack raphide idioblasts. All are multiovulate, with bitegmic ovules. The Petrosavieae are marked by the presence of septal glands and incomplete syncarpy. Tepals and stamens adhere to the ovary in the Hewardieae and the Petrosavieae but not in the Tricyrteae. Two vascular bundles occur in the stamens of the Hewartlieae and Tricyrtis latifolia. Ventral bundles in the upper part of the ovary of the Hewardieae are continuous with compound septal bundles and placental bundles in the lower part. Putative ventral bundles occur in the alternate position in the Tricyrteae and putative placental bundles in the opposite. position in the Petrosavieae. The dichtomously branched stigma in each carpel of the Tricyrteae is supplied by a bifurcated dorsal bundle.     

Entwicklungsgeschichte und Ultrastruktur von Pollenkitt und Exine bei nahe verwandten entomophilen und anemophilen Angiospermensippen derAlismataceae,Liliaceae, Juncaceae,Cyperaceae, Poaceae undAraceae

Some closely related members of the monocotyledonous familiesAlismataceae, Liliaceae, Juncaceae, Cyperaceae, Poaceae andAraceae with variable modes of pollination (insect- and wind-pollination) were studied in relation to the ultrastructure of pollenkitt and exine (amount, consistency and distribution of pollenkitt on the surface of pollen grains). The character syndromes of pollen cementing in entomophilous, anemophilous and intermediate (ambophilous or amphiphilous) monocotyledons are the same in principal as in dicotyledons. Comparing present with former results one can summarize: 1) The pollenkitt is always produced in the same manner by the anther tapetum in all angiosperm sub-classes. 2) The variable stickiness of entomophilous and anemophilous pollen always depends on the particular distribution and consistency of the pollenkitt, but not its amount on the pollen surface. 3) The mostly dry and powdery pollen of anemophilous plants always contains a variable amount of inactive pollenkitt in its exine cavities. 4) A step-by step change of the pollen cementing syndrome can be observed from entomophily towards anemophily. 5) From the omnipresence of pollenkitt in all wind-pollinated angiosperms studied one can conclude that the ancestors of anemophilous angiosperms probably have been zoophilous (i.e. entomophilous) throughout.

     

Identification and Characterization of the First Equine Parainfluenza Virus 5

正Dear Editor,Parainfluenza virus 5 (PIV5), known as canine parainfluenza virus in the veterinary field, is a negative-sense,nonsegmented, single-stranded RNA virus belonging to the Paramyxoviridae family (Chen 2018). The virus was first reported in primary monkey kidney cells in 1954 (Hsiung1972), then it has been frequently discovered in various