Double Ionization of Helium by Partially Stripped Oxygen Ions

New measurement of the ratio of the double ionization cross section to that of the single ionization of helium induced by 2.0-7.5 MeV partially stripped O^(q+) ion(q=1,2,3,4)is presented.Combining the measured data with the Olson-Schlachter scaling,the double ionization cross section of helium by partially stripped oxygen ion is obtained.It is found that the v/qeff dependence of the obtained double ionization cross section agrees well with the(v/qeff)^(-4) law.

少量细胞输入的自制转录组测序文库构建试剂评测

目的·验证基于SMART(switching mechanism at 5'end of RNA template)技术自制的转录组测序文库构建试剂(DIY试剂)替代昂贵的商业化试剂TaKaRa SMART-Seq v4试剂盒(TaKaRa试剂)的可行性。方法·选取4只8周龄雌性C57BL/6小鼠,随机分为2组:一组作为对照组,不进行处理;另一组向小鼠腹腔内注射1 mL浓度为4%的巯基乙酸盐肉汤,诱导巨噬细胞。经过72 h后,分离腹腔巨噬细胞并提取RNA,用DIY试剂和TaKaRa试剂分别进行cDNA文库的构建。经二代测序后,利用生物信息学分析方法从数据质量、基因差异表达分析、KEGG(Kyoto encyclopedia of genes and genomes)通路富集分析3个方面探究不同建库试剂对转录组测序结果的影响。结果·DIY试剂和TaKaRa试剂处理的样品数据质量良好;2种试剂捕获转录本的能力相近;样品所测序列在基因上的覆盖度均匀且一致性较高;差异表达基因以及通路富集的分析结果基本一致。结论·DIY试剂可替代TaKaRa试剂进行少量细胞的转录组测序文库构建,并降低建库成本。

除草剂减量施用对春播青贮玉米田杂草的防效

河北省春播青贮玉米田杂草优势种群为灰绿藜和狗尾草,为了提升春播青贮玉米田除草剂防效、减少除草剂的使用量,选用2种玉米苗后除草剂:30%硝·烟·莠去津可分散油悬浮剂和24%烟嘧·莠去津可分散油悬浮剂,在春播青贮玉米区研究减量1/4施用对田间杂草的防除效果。结果表明,30%硝·烟·莠去津可分散油悬浮剂对青贮玉米田间杂草的防效优于24%烟嘧·莠去津可分散油悬浮剂。30%硝·烟·莠去津可分散油悬浮剂减量1/4处理对杂草的防控效果与常规用量处理基本相当;24%烟嘧·莠去津可分散油悬浮剂减量1/4处理在后期对杂草的防控效果下降。2种药剂减量1/4处理的青贮玉米鲜草产量与常规用药量处理的产量相比差异不显著。综合比较,30%硝·烟·莠去津可分散油悬浮剂减少1/4用药量,于玉米苗后喷药处理的除草效果优于其他施药处理。

胆管癌的光动力治疗

胆管癌是种恶性程度很高的消化道肿瘤,且超过一半的患者在诊断时已是疾病晚期,错失了手术的机会。光动力疗法(PDT)是一种局部消融方法,它使用系统性光敏剂,优先聚集在恶性细胞中,并被非热光激活,通过氧自由基介导的过程导致恶性细胞的破坏。胆管癌的PDT潜在治疗方案包括联合化疗、联合支架植入、复发肿瘤的术后治疗,或对患者进行治疗使肿瘤降期后行根治性手术。在治疗胆汁淤积的同时,PDT疗法可提高生存率和生活质量,并减少肿瘤生长。

厦门沿海的砂壳纤毛虫(原生动物,纤毛门,砂壳目)

对厦门沿海6个代表性站位砂壳纤毛虫进行了为期1年的采集,共分离鉴定了27种砂壳纤毛虫,其中拟铃虫属Tintinnopsis 20种,薄铃虫属Leprotintinnus 3种,类铃虫属Codonellopsis 2种,领细壳虫属Stenosemella 1种以及网纹虫属Favella 1种。对该5属27种砂壳纤毛虫进行形态学描述,并提供了显微照片,其中侧胀拟铃虫Tintinnopsis ventricosoides Meunier,1910为中国新记录种。

交直流配电系统的典型网架结构研究

该文针对交直流配电网特点,借鉴交流配电系统典型架构,总结了接线模式的选择原则。对不同网架结构在供电质量、运行的可靠性与稳定性等方面进行对比,将交直流配电系统的网架结构进行归类,总结为辐射式、环型、手拉手结构、网格式、多分段多联络式五种典型架构。对其结构特点、拓扑方式等深入研究,介绍了各自的适用场合与实际应用场景。

Expression and contribution of microphthalmia-associated transcription factor to the melanin deposition in Liancheng white ducks

The present study investigates the expression of microphthalmia-associated transcription factor(MITF) and its contribution to the melanin deposition in Liancheng white ducks.Nested PCR was used to clone the MITF gene sequence from the skin tissue of female Liancheng white ducks.Ultraviolet spectrophotometry was used to detect the melanin deposition.MITF mRNA expression and melanin deposition in different tissues and organs were detected and their correlation was analyzed.The MITF gene(GenBank number: MG516570) was 1 323 bp in length,contains a complete CDS region(34-1 323 bp) and codes 429 amino acids with 100% homology to the MITF of Anas platyrhynchos and over 95% homology to those of Gallus gallus and Coturnix japonica.Genetic evolution analysis reveals a close relationship of Liancheng white ducks with A.platyrhynchos,and also to lesser extents with Anser cygnoides,silky fowl and G.gallus,as well as Sus scrofa,Ovis aries and other mammals.Real-time quantitative PCR(qPCR) analysis demonstrated that MITF was expressed in skin,gizzard,liver,kidney and muscle,and of these tissues,its expression was the highest in the skin tissue(skin>gizzard>liver>kidney>muscle).Ultraviolet spectrophotometry showed that melanin deposition was positively correlated with the MITF expression level in these five tissues and organs(P<0.05).Together,these results demonstrated a tissue-specific pattern of MITF expression and a positive correlation between MITF expression and melanin deposition,indicating that MITF expression may contribute to the melanin deposition in Liancheng white ducks.

高职院校构建青少年科技创新师资培训基地建设研究——以天津滨海职业学院为例

文章从讲述其研究意义开始,分析并提炼出职业院校以“科创、科普、科研”为主线,努力服务社会,积极构建青少年科技创新师资培训体系的实践和体会。