三级串联垂直潜流人工湿地的脱氮性能及微生物学特征

探究了3种水力负荷(HLR)下三级串联垂直潜流人工湿地(T-VFCWs)对农村生活污水的处理效果,并解析了系统中的氮素转化机制。结果表明: 当系统HLR由0.10增至0.20 m³·m^-2·d^-1时,T-VFCWs始终保持着对农村生活污水高效的处理效果,系统出水水质满足《城镇污水处理厂污染物排放标准》(GB 18918—2002)一级A标准。T-VFCWs中顺次连接的3个VFCW单元(标记为V-1、V-2和V-3)在限氧环境下因其进水水质的差异可形成各自不同的氮素转化途径,并通过协同作用实现系统的高效脱氮。当T-VFCWs在试验期间连续运行时,V-1、V-2和V-3中主要的脱氮途径分别为短程硝化/反硝化作用、基于亚硝化的全程自养脱氮(CANON)作用和反硝化作用,上述3单元对进水中总氮(TN)和NH₄⁺-N去除的贡献率分别为(51.3±4.4)%和(63.7±2.6)%、(30.9±4.8)%和(35.5±4.5)%、(17.8±5.0)%和(0.8±0.1)%。该研究可为组合式人工湿地的研发及工程化应用提供科学依据和技术支撑。     

不同训练方式对大鼠骨骼肌纤维类型转化和CaMK II/MEF2传导途径的影响*

目的: 探讨间歇速度训练和耐力训练对大鼠骨骼肌纤维类型转化及钙调蛋白激酶/肌细胞增强因子2(CaMK II/MEF2)信号传导通路的影响。方法: 成年雄性SD大鼠(8周龄)18只,随机分成间歇速度训练组(IST),耐力训练组(ET),设空白组(C),每组6只,IST组采用75 m/min×1 min、20 m/min×1 min的交替训练6次,跑台坡度15,持续时间12 min/d;ET组采用速度30 m/ min、跑台坡度7、持续时间90 min/d的耐力训练。干预8周后,分别取小鼠右侧胫骨前肌、比目鱼肌,酶联免疫吸附法检测骨骼肌琥珀酸脱氢酶(SDH)、乳酸脱氢酶(LDH)活性,ATP酶染色法观察I、Ⅱ型肌纤维面密度、数密度变化情况,SDS-PAGE凝胶电泳技术观察骨骼肌MHC亚型百分比含量、骨骼肌mRNA表达谱测序分析及qRT-PCR技术检测CaN、CaMKII、MEF2水平。结果: 相比C组,ET组SDH活性显著上升,LDH活性降低(P＜0.05);IST组胫骨前肌中LDH活性值升高(P＜0.01)。ET组胫骨前肌MHCIIa%升高,MHCIIb%降低(P＜0.05),比目鱼肌MHCI% 和MHCIIa%升高,MHCIIb%均降低(P＜0.05)。相比IST组,ET组胫骨前肌MHCIIx%升高(P＜0.05)。相比C组,ET组胫骨前肌 I、II 型纤维纤维密度上升,IST组II型纤维纤维密度提高,IST组、ET组比目鱼肌I型纤维纤维密度上升(P＜0.05)。相比C组,ET组骨骼肌CaN、CaMKII、MEF2 mRNA表达水平增高,IST组CaN、CaMKII、MEF2 mRNA表达水平下降(P＜0.01)。Illumina高通量测序筛选骨骼肌纤维转化相关因子及关联分析,运动干预促使骨骼肌纤维转化相关因子表达变化富集于TGF-β/Smad3、CaN/MEF2、AdipoQ等信号通路,而耐力训练显著提高骨骼肌纤维转化、干细胞功能相关信号通路的富集。结论: 耐力训练促进向氧化型肌纤维转化(慢肌),而间歇速度训练向酵解型肌纤维转化(快肌),并伴随着CaMK II/MEF2传导途径中CaN、CaMKII、MEF2基因的高表达。     

丹酚酸B对肝癌荷瘤小鼠抑瘤作用及对肝纤维化的影响

摘要 目的：探讨丹酚酸B(salvianolic acid B,Sal B)对肝癌荷瘤小鼠抑瘤作用及对肝纤维化的影响。方法：将HepG2肝癌细胞株皮下注射于裸鼠左腋下成瘤,将荷瘤小鼠(n=42)随机平分为三组：模型组、Sal B 1组与Sal B 2组。Sal B 1组与Sal B 2组于造模成功当天开始分别给予10 mL/kg/d和15 mL/kg/d丹酚酸B进行灌胃,模型组给予等量生理盐水灌胃,每周 2次,连续 4周。结果：治疗第2周与第4周后,Sal B 1组、Sal B 2组的移植瘤重量均低于模型组(P<0.05),抑瘤率高于模型组(P<0.05),Sal B 1组与Sal B 2组对比差异有统计学意义(P<0.05)。Sal B 1组、Sal B 2组肝脏系数与肝脏表面癌结节数目均低于模型组(P<0.05),Sal B 2组低于Sal B 1组(P<0.05)。Sal B 1组、Sal B 2组血清天门冬氨酸氨基转移酶(Aspartate transaminase,AST)、丙氨酸氨基转移酶(Alanine transaminase,ALT)含量均低于模型组(P<0.05),Sal B 2组低于Sal B 1组(P<0.05)。Sal B 1组、Sal B 2组肝组织转化生长因子-β1(Transforming growth factor-beta 1,TGF-β1)、Smad3蛋白相对表达水平均低于模型组(P<0.05),Sal B 2组低于Sal B 1组(P<0.05)。结论：Sal B在肝癌荷瘤小鼠中能发挥抑瘤作用,可抑制血清ALT与AST的释放,其可能是通过TGF-β1/Smad3信号发挥抗肝纤维化-肝癌作用。     

转ChIFN-γ基因油菜植株的建立

干扰素(interferons, IFNs)是一类抗病毒、抗肿瘤、抗细胞增殖等作用的高活性、多功能诱生性糖蛋白.采用农杆菌介导法将含鸡γ 干扰素 (chicken interferon-γ, ChIFN-γ) 基因的植物表达载体pSW NGN导入油菜下胚轴和子叶柄. 经筛选和分化,获得了62株抗性再生植株, 通过葡糖醛酸酶GUS (β-glucuronidase,GUS)活性检测、PCR检测及Southern杂交检测,确定获得2株单拷贝转ChIFN-γ 基因油菜. ELISA定量检测转基因植株中的ChIFN-γ 蛋白.结果表明,转基因植株ChIFN-γ 蛋白表达量最高可达1 120 pg/g鲜重.该研究为植物生物反应器生产ChIFN-γ 口服疫苗蛋白的开发及应用奠定了基础.     

1O2-Mediated and EXECUTER-Dependent Retrograde Plastid-to-Nucleus Signaling in Norflurazon-Treated Seedlings of Arabidopsis thaliana

Chloroplast development depends on the synthesis and import of a large number of nuclear-encoded pro- teins. The synthesis of some of these proteins is affected by the functional state of the plastid via a process known as retrograde signaling. Retrograde plastid-to-nucleus signaling has been often characterized in seedlings of Arabidopsis thaliana exposed to norflurazon （NF）, an inhibitor of carotenoid biosynthesis. Results of this work suggested that, throughout seedling development, a factor is released from the plastid to the cytoplasm that indicates a perturbation of plastid homeostasis and represses nuclear genes required for normal chloroplast development. The identity of this factor is still under debate. Reactive oxygen species （ROS） were among the candidates discussed as possible retrograde signals in NF-treated plants. In the present work, this proposed role of ROS has been analyzed. In seedlings grown from the very beginning in the presence of NF, ROS-dependent signaling was not detectable, whereas, in seedlings first exposed to NF after light-dependent chloroplast formation had been completed, enhanced ROS production occurred and, among oth- ers, 1O2-mediated and EXECUTER-dependent retrograde signaling was induced. Hence, depending on the developmental stage at which plants are exposed to NF, different retrograde signaling pathways may be activated, some of which are also active in non-treated plants under light stress.     

农杆菌介导的日本落叶松胚性细胞遗传转化研究

基于体细胞胚胎发生技术平台,利用携带pSuper1300+质粒,以潮霉素为筛选标记基因的农杆菌GV3101介导日本落叶松遗传转化,对植物受体材料生理状态、农杆菌浓度和浸染时间以及共培养时间等影响因素进行了研究、分析和讨论.结果表明:综合优化各影响因素,生长旺盛的日本落叶松胚性细胞,经浓度为0.4(OD600)的农杆菌浸染10min,共培养2d,再用含400mg/L的头孢霉素的液体培养基清洗脱菌,然后在含400mg/L的头孢霉素固体培养基上恢复培养,并置于含5mg/L潮霉素的固体培养基上多次筛选,最终共获得54个抗性细胞系,转化率平均为0.94个/g.PCR检测鉴定,所有抗性细胞系均为阳性转化体,并排除了农杆菌污染导致的假阳性.研究建立并优化了农杆菌介导的日本落叶松遗传转化技术,为进行遗传改良和基因功能鉴定提供有利平台.     

《科学-转化医学》：新型水凝胶生物材料可修复膝盖软骨

据每日科学网1月14日报道。美国约翰·霍普金斯大学医学院报告称,他们开发出一种新型水凝胶生物材料。在软骨修复手术中将其注入骨骼小洞,能帮助刺激病人骨髓产生干细胞,长出新的软骨。在临床试验中,新生软骨覆盖率达到86％,术后疼痛也大大减轻。相关论文发表在1月9日出版的《科学-转化医学》上。     

Induced Pluripotency for Translational Research

The advent of induced pluripotent stem cells （iPSCs） has revolutionized the concept of cellular reprogramming and potentially will solve the immunological compatibility issues that have so far hindered the application of human pluripotent stem cells in regenerative medicine. Recent findings showed that pluripotency is defined by a state of balanced lineage potency, which can be artificially instated through various procedures, including the conventional Yamanaka strategy. As a type of pluripotent stem cell, iPSCs are subject to the usual concerns over purity of differen- tiated derivatives and risks of tumor formation when used for cell-based therapy, though they pro- vide certain advantages in translational research, especially in the areas of personalized medicine, disease modeling and drug screening, iPSC-based technology, human embryonic stem cells （hESCs） and direct lineage conversion each will play distinct roles in specific aspects of translational medi- cine, and continue yielding surprises for scientists and the public.     

《科学-转化医学》：霍乱正在改变疫区居民的基因组

据《科学》杂志网站近日报道,霍乱每年夺去成千上万人的生命,但人体并没有坐以待毙,研究人员现已找到证据：在霍乱流行的孟加拉国,当地人的基因组已经进化出多种不同的方式来应对这种疾病。这是人类进化发生在现代社会的一个引人注目的例子。研究传染病对人类进化的影响将有助于设计更有效的疫苗。