转基因甜菜GTSB77品系特异性实时荧光聚合酶链式反应检测方法建立

目的 为实现转基因甜菜GTSB77的标识管理,建立其品系特异性实时荧光聚合酶链式反应(PCR)检测方法。方法 针对GTSB77的3′端外源插入片段与甜菜基因组DNA之间的邻接区序列设计引物和探针,建立GTSB77品系特异性实时荧光PCR检测方法,并对该方法的特异性、灵敏度和重复性进行检测。结果 建立的GTSB77检测方法特异性强,定量限(LOQ)为16拷贝,扩增效率为102%,重复性测试结果相对标准偏差(RSD)介于0.21%～1.66%之间。结论 建立的实时荧光PCR方法可应用于GTSB77的鉴定检测。     

壳聚糖、姜紫苏提取液涂膜应用于烤制兔腿保鲜

研究了天然保鲜剂壳聚糖与姜紫苏混合提取液维持烤兔腿品质和延长其货架期的作用效果。分别以不同质量浓度壳聚糖(Ch 0.5 g/d L,Ch 1 g/d L)、不同体积分数姜紫苏提取液(Gp5%,Gp 10%)和两者的复配保鲜液(Mix1:Ch 1 g/d L+Gp 10%(体积分数),Mix2:Ch 0.5 g/d L+Gp5%(体积分数))浸泡涂膜处理烤制兔腿,并检测4℃冷藏烤兔腿16 d贮藏期内的p H值、TVB-N值、POV值、TBA值、菌落总数和感官评分的动态变化。结果表明,经保鲜剂涂膜处理的烤兔腿在储藏期间的p H值、TVB-N值、POV值、TBA值、菌落总数均较对照组低;壳聚糖具有比姜紫苏提取液更优的抗菌作用,而姜紫苏提取液具有比壳聚糖更强的抗氧化作用和对烤兔腿色泽的保护作用;壳聚糖和姜紫苏提取液的复配在抗菌和抗氧化性能上具有协同作用,且浓度越高抗菌及抗氧化效果越优;但高浓度复配保鲜液Mix1使样品气味可接受性稍有降低。复配保鲜液Mix2可延长烤兔腿的保鲜期至第16天,且烤兔腿具有较好的气味品质。     

基于BALB/C小鼠模型评价牛乳αs1-酪蛋白的致敏特性

目的:评价过敏原的过敏症机理。方法:首先通过口腔灌胃的致敏方式建立αs1-酪蛋白致敏的BALB/C小鼠模型,通过测定小鼠特异性IgE抗体水平进行模型鉴定。评价αs1-酪蛋白对小鼠肥大细胞蛋白酶、组胺、细胞因子水平的影响,并进行临床和病理切片观察。结果:第42天用αs1-酪蛋白大剂量灌胃小鼠后,各组小鼠特异性IgE抗体水平显著升高,都产生不同程度的过敏症状,且中、高剂量组小鼠过敏反应强于低剂量组;以阴性小鼠为对照,致敏小鼠的肥大细胞蛋白酶、组胺、IL-4、IL-5、IL-10和IFN-γ细胞因子含量均显著升高,且随着致敏剂量的增加而增加;组织病理切片结果显示:αs1-酪蛋白中剂量和高剂量组小鼠产生了明显的炎症反应,局部肺泡隔塌陷或增厚,脾脏和胸腺中有淋巴结病灶产生,且小肠黏膜间质有炎细胞浸润。结论:基于BALB/C小鼠模型进一步揭示了αs1-酪蛋白的致敏机理。     

超细纤维合成革的染色与功能整理研究进展

为了解决超细纤维合成革在制备、染色以及功能整理等方面出现的问题,系统阐述了超细纤维合成革的发展历程以及未来超细纤维合成革的发展方向;分析了染色工艺、染色助剂、染色基布的改性对聚酰胺超细纤维合成革染色性能的影响,评述了聚酯超细纤维合成革的染色现状;总结了国内超细纤维合成革经功能整理后的附加性能,包括阻燃、防污、抗静电、抗菌、耐寒、调温等。最后指出了未来超细纤维合成革在制备方式、高性能染色以及功能化整理方面应大力发展的方向,以对企业的产品优化升级、提高产品的市场竞争力提供指导。     

Use of UV-C treatment to inhibit the microbial growth and maintain the quality of Yali pear

Abstract: The effects of UV-C radiation on microbial growth in vitro (Monilinia fruticola) and in inoculated Yali pears (Pyrus bretschneideri Rehd.) were investigated. Moreover, postharvest quality and the activities of defense and antioxidant enzymes were analyzed after the pears were exposed to UV-C irradiation at an energy level of 5 kJ m⁻².The results showed that spore germination of M. fructicola was significantly inhibited by each of the 3 doses (1, 5, and 10 kJ m⁻²) in vitro. In the in vivo assays, lesion diameter on the fruit being inoculated before or after the UV-C treatment was both significantly lower than that on the fruit of control. Meanwhile, the activities of phenylalanine ammonia lyase, β-1,3-glucanase, superoxide dismutase, catalase, and glutathione reductase were induced to high levels by UV-C treatment. We conclude that UV-C treatment could reduce postharvest disease by the germicidal and induced effects and maintain the quality by enhancing the antioxidant enzyme activities. Practical Application: UV-C radiation has recently been proposed as a new technology to avoid chemical fungicides. However, there are few studies regarding the effect of UV-C treatment on Yali pear. In this study, we found that 5 kJ m⁻² UV-C irradiation can control postharvest disease and maintain the quality of Yali pear. This method may be applied to reduce the decay of Yali pears during exporting and storage.     

单增李斯特菌感染RAW264.7细胞转录组差异表达分析

为了探讨单核细胞增生李斯特菌（Listeria monocytogenes,LM）感染前后RAW264.7细胞基因表达谱变化,筛选关键功能基因和通路,为探究其致病机制奠定基础,本研究以感染复数（MOI）10的LM 感染RAW264.7细胞6 h后,提取细胞RNA进行转录组测序,选取感染组与对照组相比差异倍数≥1.5且P<0.05的差异表达基因进行GO和KEGG富集分析,并通过RT-qPCR验证部分差异基因。转录组结果显示RAW264.7细胞在感染LM前后有1 782 个基因差异表达,其中上调为989,下调为793。GO分析结果主要涉及免疫系统过程、免疫反应、细胞程序性死亡调控等。KEGG分析结果显示,显著富集的通路有细胞因子-受体相互作用、肿瘤坏死因子信号通路、IL-17信号通路等。RT-qPCR验证试验结果显示,随机选择的11 个显著差异基因表达倍数趋势与测序结果一致。该研究为进一步深入研究LM的致病机制奠定了基础。     

论我国北煤南运建设CWF加工业和CWF管道的可行性

据我国专家预测,我国在2030年之前,煤炭仍将是主要能源,北煤南运和节煤减排仍是长期的任务。分析了第二代水煤浆燃料(CWF)的优点:流变性稳定,储存期长(两年);加工过程并不复杂;可管输,埋于地下安全不冻,不受恶劣气候影响,无爆炸危险,可沿铁路铺设,不占农田。CWF发电NOx排放量比煤粉发电低20%～30%,又无堆煤场及煤粉加工粉尘危害。建议十二五规划中引进该项技术,在山西、陕西、内蒙古自治区西部交界地区建设CWF生产基地、集输管网并沿北煤南运三大铁路运煤通道敷设3条529mm实验CWF管道。采用开式流程和滚动开发技术,边建设边投产运行,尽快产生经济效益,立竿见影缓解北煤南运紧张度,以保证运输安全。     

Spectral and Laser Properties of Yb:LuAG Transparent Ceramics Fabricated by Tape Casting Method

Yb³⁺‐doped LuAG laser ceramics with different Yb³⁺‐doping concentrations were successfully fabricated by nonaqueous tape casting method and vacuum sintering technology. XRD patterns and SEM morphologies of the ceramics were presented. The optical in‐line transmittance of the Yb‐doped LuAG ceramics was about 83% at 1030 nm. The fluorescence lifetime of annealed and unannealed ceramic samples was compared. From the spectroscopic properties, it can be seen that the ceramics had a large emission cross section of 2.9 × 10^?20 cm² with a FWHM of about 7.2 nm at 1030 nm. Under 100% population inversion, the maximum gain coefficient was estimated to be 12.4 cm^?1 at 1030 nm. With a fiber‐coupled diode laser as pump source, CW laser at 1030 nm was demonstrated and the maximum output power of 338.9 mW was achieved with a slop efficiency of 19%. A tuning range from 1028 to 1036 nm was obtained.     

Re‐exploration of the Codon Context Effect on Amber Codon‐Guided Incorporation of Noncanonical Amino Acids in Escherichia coli by the Blue–White Screening Assay

The effect of codon context on amber codon‐guided incorporation of noncanonical amino acids (NAAs) has been previously examined by antibiotic selection. Here, we re‐explored this effect by screening a library in which three nucleotides upstream and downstream of the amber codon were randomised, and inserted within the lacZ‐α gene. Thousands of clones were obtained and distinguished by the depth of blue colour upon exposure to X‐gal. Large‐scale sequencing revealed remarkable preferences in nucleotides downstream of the amber codon, and moderate preferences for upstream nucleotides. Nucleotide preference was quantified by a dual‐luciferase assay, which verified that the optimum context for NAA incorporation, AATTAGACT, was applicable to different proteins. Our work provides a general guide for engineering amber codons into genes of interest in bacteria.