沙枣细胞悬浮培养体系的建立

分别以沙枣幼嫩叶片,茎段为外植体诱导沙枣愈伤组织,选择生长旺盛的松散愈伤组织进行细胞悬浮培养,探讨了培养基种类和激素组合对其产生的影响.结果表明,最适的沙枣愈伤组织诱导培养基为NT(包括0.1 mg·L-1BA和0.1 mg·L-1TDZ);沙枣悬浮细胞在MS,NT,WPM,B5和IS培养基中均可生长,其中在NT培养基中生长状态最好,呈现生长均一的绿色疏松状态.激素组合对沙枣细胞生长影响很大,其中附加BA 0.1 mg·L-1和TDZ 0.1 mg·L-1组合的NT液体培养基可获得大量繁殖速度快、生长均匀一致的悬浮细胞,细胞增长系数达5.73.HPLC测定结果证明沙枣细胞中含有一定量的浓缩鞣质达5.2022 mg/gDW,这为利用沙枣悬浮细胞生产次生代谢产物提供了一条有效途径.     

用基因疫苗制备H9亚型禽流感病毒单克隆抗体

用H9亚型禽流感病毒(AIV)HA基因反转录cDNA第一链PCR扩增其HA基因,PCR产物与pcDNA3.1( )质粒构建重组质粒作为基因疫苗免疫8周龄Balb/C小鼠,细胞融合后用血凝抑制试验(HI)和ELISA试验检测细胞培养上清,各获得一株阳性细胞株,经3次亚克隆后都能稳定分泌H9AIV特异性抗体。特异性检测与NDV、H5亚型AIV、产蛋下降综合症(EDS76)病毒毒株没有反应,2株单抗经亚型鉴定均为IgG2b,轻链的亚型为kappa链。所获得的单克隆抗体将在禽流感快速诊断和疾病预警监控中发挥重要作用。     

胶原诱导性关节炎小鼠CD4^＋T细胞亚群表达酪氨酸羟化酶的作用

目的：本研究应用胶原诱导性关节炎（CIA）的动物模型,通过研究CD4＋T细胞亚群表达酪氨酸羟化酶（TH）的变化与作用,探讨CIM＋T细胞亚群来源的儿茶酚胺与CIA的炎症反应之间的关系。方法：雄性DBA／1小鼠36只随机分为对照组、35天模型组和55天模型组（n=12）。用Ⅱ型胶原（cⅡ）乳剂免疫DBA／1小鼠诱导CIA,在初次免疫后第35天和55天进行关节临床评分并检测血清中抗cⅡ IgG抗体水平的变化。用Western blot法检测肠系膜淋巴结中1h1、Th17、Th2和Treg细胞的特异性转录因子及其细胞因子以及TH表达的变化。用流式细胞术检测肠系膜淋巴结中表达TH的CD4＋T细胞亚群数目的变化。结果：CIA小鼠在发病早期（初次免疫后第35天）和发病晚期（初次免疫后第55天）临床评分和血清中抗cⅡ IgG抗体水平显著升高。CIA小鼠肠系膜淋巴结中1h1和Th17细胞的特异性转录因子和细胞因子表达增加而Th2和Treg细胞的细胞因子表达减少。CIA小鼠肠系膜淋巴结中TH的表达增加,且CD4＋T细胞中TH＋的细胞数目增多,这主要是来自CD4＋T细胞亚群中Thl和rIh17细胞的作用。结论：CIA小鼠肠系膜淋巴结中存在CIM＋T细胞亚群来源的儿茶酚胺的增加,可能在cn的发展过程中具有一定的抗炎作用。     

基于人工巢试验分析黄腹角雉巢卵捕食者

2007年至今,我国在陕西宁陕、铜川和千阳,以及河南董寨和浙江德清初步建立了朱鹮(Nipponia nippon)野化放归种群。鸟类的繁殖行为是其生活史策略的重要组成部分,可以反映动物个体的营养状态、所处栖息地的质量,以及对栖息地的适应等。本文报道浙江德清朱鹮野化放归种群的繁殖行为,旨在了解其在我国南方的适应情况,为最终建立中国朱鹮南方种群提供科学支撑。本研究于2018年4和5月及2020年3至5月对浙江德清野化放归朱鹮的3个繁殖巢进行实时监测,记录孵卵期和育雏期繁殖行为,总记录时长为134 d,有效数据时长为2 958 h。利用线性混合模型探究朱鹮衔巢材频率、孵卵期以及育雏期行为的影响因子,采用Spearman相关分析检验朱鹮翻卵频率与孵卵进程的关系,建立Logistic回归模型探究朱鹮亲鸟暖雏时长随雏鸟日龄的变化情况,并利用one-way ANOVA分析德清朱鹮与陕西洋县野生种群和其他野化放归种群的换巢频率差异。结果表明,德清朱鹮平均窝卵数3.7 ± 0.3,孵化成功率90.9%,雏鸟出飞率100.0%;繁殖的不同时期、营巢条件和亲鸟性别均显著影响朱鹮的衔巢材频率;朱鹮的翻卵频率随孵卵进程显著下降;亲鸟的暖雏时长在雏鸟11日龄时下降率最大;育雏的不同时期对朱鹮的暖雏时长、换巢频率以及喂雏频率有极显著的影响;环境温度较高可能是导致德清朱鹮比洋县野生种群提前产卵的原因之一;较高的平均窝卵数与出飞成功率表明,朱鹮对我国南方的栖息地较为适应。鉴于本研究发现利用人工巢筐营巢的亲鸟花费更多时间补充巢材,表明人工巢筐的结构和大小有必要优化,建议在今后设计时加大筐壁仰角并减小深度、扩大外径,使人工巢筐更接近于自然巢的盘状结构,同时,应将巢筐底部设计成多孔透气、利于排水的结构,以适应我国长江中下游地区湿热多雨的气候。     

βLCR对β地中海贫血基因在转基因小鼠体内表达的影响

目的:明确在转基因小鼠体内,βLCR对β地中海贫血基因表达的影响。方法：将完整人β-IVSⅡ-654地中海贫血基因,与串连了人βLCR的β-IVSⅡ-654地中海贫血基因分别经显微注射法制作转基因小鼠;荧光定量RT-PCR法检测β-IVSⅡ-654地贫基因在转基因小鼠体内的表达;采用统计分析比较2类转基因鼠中外源基因的表达量。结果：成功建立2类整合了人β-IVSⅡ-654地贫基因的转基因小鼠模型。荧光定量RT-PCR分析结果表明,在整合了串连人βLCR的β-IVSⅡ-654地贫基因的小鼠体内,外源基因mRNA的表达量远高于仅整合β-IVSⅡ-654地贫基因的小鼠（统计分析P值 ）。结论：βLCR核心片段的存在可以使β-珠蛋白基因家族（包括β-地贫基因）在转基因小鼠体内获得高效表达的必要条件。     

Preoperative C-Reactive Protein/Albumin Ratio Predicts Prognosis of Patients after Curative Resection for Gastric Cancer

BACKGROUND: An elevated preoperative C-reactive protein/albumin (CRP/Alb) ratio has been reported to be associated with a poor prognosis for hepatocellular carcinoma. The aim of the present study was to investigate the prognostic value of the preoperative CRP/Alb ratio and compare it with other systemic inflammatory response markers in patients with gastric cancer (GC). METHODS: A retrospective study was performed in 455 patients with GC undergoing curative resection. We investigated the correlations between the preoperative CRP/Alb ratio and overall survival (OS). Kaplan-Meier and Cox regression models were used to assess independent prognostic factors. The area under the curve was used to compare the prognostic value of different markers. RESULTS: On multivariate analysis, the CRP/Alb ratio were independently associated with OS in patients with GC (hazard ratio: 1.626; 95% confidence interval: 1.191-2.219; P = .002), along with age (P = .003), preoperative body weight loss (P = .001), tumor location (P = .008), metastatic lymph node ratio (P < .001), and seventh tumor-nodes-metastasis stage (American Joint Committee on Cancer) (P = .007). However, several other systemic inflammation–based prognostic scores (neutrophil lymphocyte ratio, platelet lymphocyte ratio and systemic immune-inflammation index, Glasgow Prognostic Score, modified Glasgow prognostic score, and high-sensitivity modified Glasgow prognostic score) were not. In addition, the CRP/Alb ratio had a higher area under the curve value (0.625) compared with several other systemic inflammation–based prognostic scores (P < .001). CONCLUSION: The preoperative CRP/Alb ratio, a system inflammation-based prognostic score, is a superior predictor of OS in patients undergoing curative resection for GC and may help to identify the high-risk patients for treatment decisions.     

放线菌萜类化合物生物合成研究进展

萜类化合物(Terpenoids)是自然界中化学结构最为丰富的一类化合物。近年来,从放线菌中分离到了一系列结构新颖的萜类化合物。通过直接克隆或基因组采掘(Genome mining)的方法,它们的生物合成基因簇被相继分离和鉴定,从而推动了放线菌中萜类化合物生物合成途径及关键酶的分子作用机理的研究。文章主要综述了近5年放线菌萜类化合物生物合成研究进展。     

Slippery Photothermal Trap for Outstanding Deicing Surfaces

Ice accumulation is a safety and operational threat in power lines,wind turbines,and transportations.Surfaces having both passive anti-icing and active deicing ...     

Involvement of phospholipase D in the low temperature acclimation-induced thermotolerance in grape berry

Both phospholipase D (PLD, EC 3.1.4.4) and salicylic acid (SA) play important roles in response to external stimulation and activating defense system in plants. However, roles of the two signals in plants during the development of thermotolerance induced by low temperature acclimation remain unclear. In the experiment presented in the paper, grape berries (Vitis vinifera L. cv. Chardonnay) were pretreated at 8 °C for 3 h and then transferred to 45 °C for heat stress. Compared with the control without low temperature pretreatment, membrane permeability and malondialdehyde (MDA) contents were reduced and the expression of HSP73 increased in the low temperature-pretreated berries under heat stress. During low temperature acclimation, PLD, SA and HSP73 could be activated. Meanwhile, the expression of HSP73 and the accumulation of free SA induced by low temperature can be inhibited by PLD activity inhibitor. All these results suggest that the activation of PLD is an early response to low temperature, and it is involved in the accumulation of free SA and the development of thermotolerance induced by low temperature acclimation.     

Differential development of murine dendritic cells by GM-CSF versus Flt3 ligand has implications for inflammation and trafficking

To gain ample numbers of dendritic cells (DCs) for investigation, or for immunotherapy, the culture of DC precursors from bone marrow in either GM-CSF and IL-4 (GM/IL4-DCs) or Flt3L (FL-DCs) has often been used. Despite their common use, the relationship of these culture-derived DCs to those in vivo, and their relative potential for use in immunotherapy, needs further elucidation. In this study we found that in contrast to FL-DCs, highly purified GM/IL4-DCs were larger and more granular, surface Mac-3(+), and were comprised of two populations (CD24(low)CD11b(high) and CD24(high)CD11b(low)). Functionally, although comparable in T cell activation, GM/IL4-DCs produced more inflammatory mediators including TNF-alpha, IL-10, CCL-2, and NO than FL-DCs upon TLR ligation. However, FL-DCs migrated more efficiently to draining lymph nodes after s.c. injection and produced a different profile of cytokines to GM/IL4-DCs. Developmentally, unlike GM/IL4-DCs, FL-DCs cannot be differentiated from CD11b(high)Ly6C(high)Ly6G(-) monocytes. Collectively, these data suggest that the GM/IL4-DCs are the equivalents of the TNF-alpha and inducible NO synthase producing DCs in vivo that emerge after inflammation whereas FL-DCs better represent the steady-state resident DCs. The differences between GM/IL4-DCs and FL-DCs have serious implications for DC-based immunotherapeutic strategies.