Multi-environment BSA-seq using large F3 populations is able to achieve reliable QTL mapping with high power and resolution: An experimental demonstration in rice

Bulked-segregant analysis by deep sequencing(BSA-seq) is a widely used method for mapping QTL(quantitative trait loci) due to its simplicity, speed, cost-effectiveness, and efficiency. However, the ability of BSA-seq to detect QTL is often limited by inappropriate experimental designs, as evidenced by numerous practical studies. Most BSA-seq studies have utilized small to medium-sized populations, with F2populations being the most common choice. Nevertheless, theoretical studies have shown that using a large population with an appropriate pool size can significantly enhance the power and resolution of QTL detection in BSA-seq, with F_(3)populations offering notable advantages over F2populations. To provide an experimental demonstration, we tested the power of BSA-seq to identify QTL controlling days from sowing to heading(DTH) in a 7200-plant rice F_(3)population in two environments, with a pool size of approximately 500. Each experiment identified 34 QTL, an order of magnitude greater than reported in most BSA-seq experiments, of which 23 were detected in both experiments, with 17 of these located near41 previously reported QTL and eight cloned genes known to control DTH in rice. These results indicate that QTL mapping by BSA-seq in large F_(3)populations and multi-environment experiments can achieve high power, resolution, and reliability.

Generation and selection of immunized Fab phage display library against human B cell lymphoma

The approval of using monoclonal antibodies as a targeted therapy in the management of patients with B cell lymphoma has led to new treatment options for this group of patients. Production ofmonoclonal antibodies by the traditional hybridoma technology is costly, and the resulting murine antibodies often have the disadvantage of triggering human anti-mouse antibody （HAMA） response. Therefore recombinant Fab antibodies generated by the phage display technology can be a suitable alternative in managing B cell lymphoma. In this study, we extracted total RNA from spleen cells of BALB/c mice immunized with human B lymphoma cells, and used RT-PCR to amplify cDNAs coding for the κ light chains and Fd fragments of heavy chains. After appropriate restriction digests, these cDNA fragments were successively inserted into the phagemid vector pComb3H-SS to construct an immunized Fab phage display library. The diversity of the constructed library was approximately 1.94× 10^7. Following five rounds of biopanning, soluble Fab antibodies were produced from positive clones identified by ELISA. From eight positive clones, FabC06, FabC21, FabC43 and FabC59 were selected for sequence analysis. At the level of amino acid sequences, the variable heavy domains （VH） and variable light domains （VL） were found to share 88-92% and 89-94% homology with sequences coded by the corresponding murine germline genes respectively. Furthermore, reactivity with membrane proteins of the B cell lymphoma was demonstrated by immunohistochemistry and western blotting. These immunized Fab antibodies may provide a valuable tool for further study of B cell lymphoma and could also contribute to the improvement of disease therapy.

Improved bias proportional navigation with multiple constraints for guide ammunition

According to the infrared guidance ammunition(GA)attacking non-maneuvering targets on the ground or sea level,an improved bias proportional navigation(IBPN) is put forward,which can meet the constraints of the impact angle and the angle of attack(AOA). The motion equations and the collision triangle for the GA and the target are established in the two-dimensional plane. In accordance with the collision triangle, the integral value of the bias term is solved and BPN is designed on the basis of the relative velocity. To ensure the new method can be solved, closedloop equation of the IBPN is deduced. Considering the limitation of the AOA and the seeker angle, a four-phase IBPN is improved by setting different phases of the bias term. At the same time, the guidance law will make the impact angle achieve the desired angle and the normal acceleration also converges to zero. The simulation results show that the improved guidance law can be applied to various flight tasks and has great potential for engineering applications.

Extraction Process of Total Flavonoids from Eucommiae Cortex and Its in vitro Antioxidant Activity

[Objectives]To optimize the extraction process of total flavonoids from Eucommiae Cortex,establish the extraction and content determination methods of its medicinal materials,and study its in vitro antioxidant activity.[Methods]The total flavonoids from Eucommiae Cortex were extracted by reflux extraction method,and the effects of extraction method,extraction solvent concentration,extraction volume,and extraction time on the total flavonoids content of the medicinal materials were explored through the single factor experiment.Orthogonal experiment was carried out to optimize the extraction process conditions,and the optimal extraction process for total flavonoids from Eucommiae Cortex was screened out.The total antioxidant capacity index was used to determine the free radical scavenging ability of the total flavonoids from Eucommiae Cortex.[Results]The optimal extraction process of total flavonoids from Eucommiae Cortex was 50%ethanol,1∶40 solid-to-liquid-ratio,and 1.5 h reflux extraction time.Through the antioxidant experiment in vitro,it is found that the total flavonoids from Eucommiae Cortex have a higher scavenging ability for the total antioxidant capacity,and there is a certain positive correlation with the mass concentration of total flavonoids.[Conclusions]This method can effectively determine the total flavonoids content of Eucommiae Cortex medicinal material,and provide a certain scientific basis for the quality standard research of the medicinal material.The total flavonoids from Eucommiae Cortex have good in vitro antioxidant activity.And the method for extracting total flavonoids from Eucommiae Cortex medicinal material in this experiment has good repeatability,high stability and feasibility.

Research Progress on Antitumor Effect and Mechanism of Panax quinquefolium Linn.

Panax quinquefolium Linn.,belonging to Panax,Araliaceae,contains a variety of active ingredients.In recent years,many studies have shown that P.quinquefolium Linn.has high value and development prospect in inhibiting colon cancer,lung cancer and breast cancer.Recent advances in studies on chemical components,antitumor effects and mechanisms of P.quinquefolium Linn.are reviewed in the paper.

Degradation kinetics and mechanism of aniline by heat-assisted persulfate oxidation

Oxidation of aniline by persulfate in aqueous solutions was investigated and the reaction kinetic rates under different temperature, persulfate concentration and pH conditions were examined in batch experiments. The results showed that, the aniline degradation followed pseudo first-order reaction model. Aniline degradation rate increased with increasing temperature or persulfate concentration. In the pH range of 3 to 11, a low aniline degradation rate was obtained at strong acid system （pH 3）, while a high degradation rate was achieved at strong alkalinity （pH 11）. Maximum aniline degradation occurred at pH 7 when the solution was in a weak level of acid and alkalinity （pH 5, 7 and 9）. Produced intermediates during the oxidation process were identified using liquid chromatography-mass spectrometry technology. And nitrobenzene, 4-4’-diaminodiphenyl and 1-hydroxy-1,2-diphenylhydrazine have been identified as the major intermediates of aniline oxidation by persulfate and the degradation mechanism of aniline was also tentatively proposed.

情景模拟训练结合Miller金字塔教学对手术室专科护士应急能力与护理技能影响的研究

目的探讨情景模拟训练结合Miller金字塔教学对手术室专科护士应急能力与护理技能的影响。方法选取2019年6月至2020年6月在电子科技大学医学院附属绵阳医院进行手术室专科轮转的灾害护理学员56人,将其按培训时间先后顺序分为对照组和研究组,每组28人。对照组采用传统带教,研究组采用情景模拟训练结合Miller金字塔教学。培训结束后通过考核专业理论知识和护理技能操作以评价专科护士培训教学效果;采用自拟考核量表评价专科护士培训的应急能力和培训效果的满意度。采用SPSS 22.0进行t检验和卡方检验。结果研究组手术室专科护士培训专业理论知识和护理技能操作考核成绩均高于对照组,差异有统计学意义(P<0.001)。研究组手术室专科护士培训应急能力考核评分均高于对照组,差异有统计学意义(P<0.001)。研究组在提升专科护理操作水平、提升突发事件应急能力、提升团队协作能力、提升分析解决问题能力、提升临床护理决策能力、提升独立思考能力及提升护患沟通能力7个方面的满意度均优于对照组,差异有统计学意义(P<0.05)。结论情景模拟训练结合Miller金字塔教学可提高手术室专科护士的应急能力、护理技能操作及培训满意度。