Rapid Differential Detection of Abrin Isoforms by an Acetonitrile- and Ultrasound-Assisted On-Bead Trypsin Digestion Coupled with LC-MS/MS Analysis

The high toxic abrin from the plant Abrus precatorius is a type II ribosome-inactivating protein toxin with a human lethal dose of 0.1–1.0 µg/kg body weight. Due to its high toxicity and the potential misuse as a biothreat agent, it is of great importance to developing fast and reliable methods for the identification and quantification of abrin in complex matrices. Here, we report rapid and efficient acetonitrile (ACN)- and ultrasound-assisted on-bead trypsin digestion method combined with HPLC-MS/MS for the quantification of abrin isoforms in complex matrices. Specific peptides of abrin isoforms were generated by direct ACN-assisted trypsin digestion and analyzed by HPLC-HRMS. Combined with in silico digestion and BLASTp database search, fifteen marker peptides were selected for differential detection of abrin isoforms. The abrin in milk and plasma was enriched by immunomagnetic beads prepared by biotinylated anti-abrin polyclonal antibodies conjugated to streptavidin magnetic beads. The ultrasound-assisted on-bead trypsin digestion method was carried out under the condition of 10% ACN as denaturant solvent, the entire digestion time was further shortened from 90 min to 30 min. The four peptides of T3A^a,b,c,d, T12A^a, T15A^b, and T9A^c,d were chosen as quantification for total abrin, abrin-a, abrin-b, and abrin-c/d, respectively. The absolute quantification of abrin and its isoforms was accomplished by isotope dilution with labeled AQUA peptides and analyzed by HPLC-MS/MS (MRM). The developed method was fully validated in milk and plasma matrices with quantification limits in the range of 1.0-9.4 ng/mL for the isoforms of abrin. Furthermore, the developed approach was applied for the characterization of abrin isoforms from various fractions from gel filtration separation of the seeds, and measurement of abrin in the samples of biotoxin exercises organized by the Organization for the Prohibition of Chemical Weapons (OPCW). This study provided a recommended method for the differential identification of abrin isoforms, which are easily applied in international laboratories to improve the capabilities for the analysis of biotoxin samples.     

益气清瘟解毒合剂拆方对流感病毒FM_1感染小鼠血清炎性细胞因子的影响

目的:动态观察益气清瘟解毒合剂拆方辛温解表法、辛凉解表法、清热解毒法、益气法(以下简称四法)对流感病毒感染小鼠血清炎性细胞因子的影响,探讨四法在对抗流感免疫损伤及其修复方面的作用机制。方法:建立流感病毒亚洲甲型鼠肺适应株FM1感染小鼠模型,采用ELISA法,在FM1感染的不同时相,动态观察四法对小鼠血清TNF-α,IL-6,IL-1,IFN-γ,IL-105种炎性细胞因子含量的影响。结果:FM1感染小鼠血清TNF-α,IL-6,IL-1,IFN-γ的含量显著增加,而IL-10的含量在感染后第1天低于正常空白组,在感染后3～7d明显高于正常组。四法中辛温解表法在FM1感染后第5天同时显著降低血清TNF-α,IL-6,IL-1的含量,并在感染后第3天及第7天,明显增加血清IL-10的含量,在一定程度上具有抑制免疫损伤的作用。辛凉解表法在FM1感染后5～7d,显著降低血清TNF-α和IL-6的含量,虽在感染后第3天,可能升高血清IL-1的含量,而在感染后第7天又明显降低IL-1的含量,同时在感染后第1～3天及第7天显著升高IL-10的含量,具有一定的抗炎性损伤的作用。清热解毒法在FM1感染后3～5d及第7天同时降低血清TNF-α,IL-6,IL-1的含量,在感染后各时相均显著升高IL-10的含量,具有较强的抑制及修复炎性损伤的作用。益气法在FM1感染后3～7d,显著降低血清TNF-α和IL-6的含量,虽在感染后第3天,可能升高血清IL-1的含量,但在感染后第7天又明显降低IL-1的含量,并且在感染后3～5d及第7天,明显增加IL-10的含量,具有一定的对抗炎性损伤的作用。辛凉解表法在FM1感染后第3天,显著增加血清IFN-γ的含量,而清热解毒法与益气法在FM1感染后1～3d及第7天明显升高血清IFN-γ的含量,具有一定的抗病毒及抑制免疫损伤的作用。结论:中药能通过纠正炎性细胞因子的失衡对抗机体的免疫损伤,并促进损伤的修复,对机体具有一定的保护作用。     

二苯氯胂对小白鼠和大鼠的急性毒性研究

目的 评估日本遗弃在华化学武器二苯氯胂(diphenylchlorarsine, DA)对环境和人畜的毒性危害.方法 通过DA对小白鼠灌胃,观察小白鼠的中毒症状,测定DA对小白鼠的LD50值;观察DA对大鼠皮肤和眼睛的刺激作用.结果 DA对小白鼠的LD50为28.07 mg/kg;对大鼠皮肤的最大无作用剂量为8.8 mg/ml(0.44 mg);对眼睛损伤的最大无作用剂量为0.7 mg/ml (0.014 mg).结论 DA可造成小鼠肝、肾、胃和食道器质性的损伤,高浓度的DA可引发大鼠皮肤炎症和眼睛晶状体混浊,严重时引起失明.     

中子弹核爆炸早期核辐射剂量的研究

目的：探讨中子弹核爆炸辐射场内瞬发中子和γ辐射的个人吸收剂Dp(10）空间分布情况。方法：对中子弹结构和原理分析的原理分析的基础上,通过建立模型,利用蒙卡罗方法（MC）粒子输运技术进行计算。结果：通过对所得数据进行系统分析,得出中子弹核爆炸瞬发中子和γ辐射的个人吸收剂量Dp(10)数值在空间分布上一些规律与特点。结：中子弹核爆炸不仅会产生高能中子辐射,而且也会产生强烈γ辐射,同时对1kt中子弹核爆炸后瞬发辐射的杀伤威力进行了评估。     

Site-specific barium toxicity to common duckweed,Lemna minor

The barium water quality standard for indigenous aquatic life in Illinois is 5 mg/l in total form. This study was conducted to test Ba phytotoxicity in various water samples, encompassing lake and stream waters with a wide variation in water quality. A total of 59 samples were collected from 18 stations. Common duckweed, Lemna minor, was used as the test organism. The results showed that Ba toxicity to duckweed was highly dependent on site-specific water quality. The Ba ion was most toxic to duckweed in waters from Hayes Creek and Horseshoe Lake, with 50% growth inhibition at concentrations 102 and 107 mg/l Ba, and least toxic in Beaucoup Creek, 0–6% growth inhibition at 400 mg/l Ba. The major factor modifying Ba toxicity was the sulfate concentration in the water samples. Regression analysis showed that the relationship between them was linear with the coefficient of determination R² = 0.68. The current water quality standard of 5 mg/l Ba (total) is considered adequate to protect common duckweed in all waters tested.     

Facile synthesis and nematicidal activity evaluation of thiophosphinyl amide [(Pz)2P(S)NHR] and thiophosphonyl diamide [(Pz)P(S)(NHR)2] (Pz = 1,3,5-trimethylpyrazole,R = biphenyl derivatives)

A series of thiophosphinyl amide [(Pz)₂P(S)NHR] and thiophosphonyl diamide [PzP(S)(NHR)₂] compounds, where Pz = 1,3,5-trimethylpyrazole and N(H)R = derivatives of 2-aminobiphenyl, were synthesized via a facile two-step process. Reaction of pyrazolyl substituted bromophosphine with 2-aminobiphenyl derivatives and further reaction with elemental sulphur affords the corresponding thiophosphinyl amide and thiophosphonyl diamide. The intermediate species was used without prior purification for reaction with sulphur to yield the target compounds. The nematicidal activity evaluation suggests that some compounds could manifest moderate nematicidal activity towards Meloidogyne incogita, which is higher than that of their amide analogue bixafen.

A series of SDHI (succinate dehydrogenase inhibitor)-like thiophosphinyl amide [(Pz)₂P(S)NHR] and thiophosphonyl diamide [PzP(S)(NHR)₂] compounds, where Pz = 1,3,5-trimethylpyrazole and N(H)R = derivatives of 2-aminobiphenyl, were synthesized via a facile two-step process. Some of their nematicidal activities towards Meloidogyne incogita are stronger than that of the amide analogue bixafen.     

Dual-purpose high-efficiency air filter paper loaded with reactive zirconium hydroxide for the filtration aerosols and degradation of chemical warfare agents

Traditional air filter papers can only filter toxic aerosols without the function of decontamination. If the poison stagnating in the paper is desorbed, it may pose a secondary threat to personnel and make it more difficult to dispose of the scrapped paper. Using an alkali-free glass fiber as the base material and zirconium hydroxide as the decontaminant, a self-decontaminating air filter paper that can degrade HD and VX simultaneously was successfully prepared by an intra-pulp addition method, with high filtration efficiency, low pressure drop and moderate tensile strength. The physicochemical properties were characterized by FE-SEM, EDX, XRD and TGA, and the results indicated that Zr(OH)₄ was dispersed uniformly in the paper and filled in the interstices of the glass fiber. The preparation of the composite material had no impact on the structure of fibers and Zr(OH)₄. The preparation technology of the self-decontaminating air filter paper was optimized. It was found that the paper with a fiber grammage of 50 g m⁻², the adhesive of 2% and a Zr(OH)₄ retention rate of 175.0 wt% could completely degrade HD and VX, whose conversion rate exceeded 99.0%, and had a tensile strength of 0.1193 kN m⁻¹, a filtration efficiency of 99.995%, and a pressure drop of 313.6 Pa. Using GC-MS to detect the decontamination products, it was speculated that HD mainly underwent hydrolysis and elimination reactions, VX mainly underwent hydrolysis and polymerization reactions, and their products were non-toxic or low-toxic. The reaction kinetics of HD and VX on the paper was investigated and the half-lives were 2.6 h and 16.2 min, respectively, which demonstrated an outstanding degradation performance. This work manifested for the first time that the air filter paper can be optimized as an efficient self-decontaminating material, which will open up new possibilities for the design and manufacture of multifunctional protective materials.

Dual-functional air filter paper with addition of Zr(OH)₄ was prepared by an intra-pulp addition method, whose filtration performance is maintained while the decontamination performance is added for HD and VX.     

Effects of polyethylene terephthalate microplastic on germination,biochemistry and phytotoxicity of Cicer arietinum L. and cytotoxicity study on Allium cepa L

Accumulation of plastic materials in terrestrial systems threatens to contaminate food chains. The aim of the current study is to determine the impact of microplastics synthesized from PET plastics (control, 50, 250, 500, 750, 1000 mg/L) with respect to morphological, biochemical impact on Cicer arietinum using standardized 72 h assay and cytotoxicity study on Allium cepa root tips. The synthesized microplastics were characterized by Scanning Electron Microscope (SEM) and Fourier Transform Infrared spectroscopy (FTIR) studies. Germination studies clearly revealed that there is a sharp decrease in germination with increasing the concentration of microplastics. Both pigment and carbohydrate levels increased up to 500 mg/L concentration, although protein levels increased with increase of microplastic dose. Catalase activity also increased with increasing microplastic concentration. Finally, cytotoxicity studies revealed significant chromosomal aberration at higher dose of microplastics. Therefore, it may be concluded that the microplastics have significant biological and structural adverse effects on plant metabolism.     

4-去乙酰化长春碱氨基酸衍生物的合成

目的:合成4-去乙酰化长春碱氨基酸衍生物,为长春碱靶向前药的合成奠定基础。方法:氨基酸N端采用苄氧羰基(Z)保护,利用混合酸酐法合成(4-去乙酰化长春碱)-氨基酸-Z,然后催化氢化得到(4-去乙酰化长春碱)-氨基酸衍生物。结果:采用新方法合成4-去乙酰化长春碱氨基酸衍生物,结构经质谱和1H-NMR确证。结论:本实验所采用的方法通用性强,优化了反应条件,反应步骤缩短,产率高,产物后处理简便,降低了实验成本。