海水养殖尾水处理系统中微生物群落对水处理阶段的响应

为了阐明南美白对虾高位池养殖尾水处理系统中不同水处理阶段微生物群落演替机制, 利用16S rRNA基因高通量测序技术分析了水体和生物膜的微生物群落结构。结果显示, 在水处理系统中主要是变形菌门(Proteobacteria)、浮霉菌门(Planctomycetes)、拟杆菌门(Bacteroidetes)、蓝细菌门(Cyanobacteria)、放线菌门(Actinobacteria)及酸杆菌门(Acidobacteria), 平均占细菌总OTU的88.61%。生物膜中生物多样性指数普遍高于水样, 与水体的共有菌为320种, 载体不同是造成群落结构差异的主要原因, 黏土陶粒和北美海蓬子(Salicornia bigelovii)根系是硝化作用的主要反应场所。在属水平上筛选出160种微生物, 主要属于变形菌门、拟杆菌门、浮霉菌门、蓝细菌门、厚壁菌门(Firmicutes)及放线菌门, 它们能够较好地区分菌群的来源及水处理的反应阶段。研究揭示了不同水处理阶段以及不同生物填料中微生物动态变化情况, 为今后的海水养殖尾水处理提供理论依据和技术参考。     

Predicting Protein Solubility by the General Form of Chou's Pseudo Amino Acid Composition: Approached from Chaos Game Representation and Fractal Dimension

Obtaining soluble proteins in sufficient concentrations is a major obstacle in various experimental studies. How to predict the propensity of targets in large-scale proteomics projects to be soluble is a significant but not fairly resolved scientific problem. Chaos game representation (CGR) can investigate the patterns hiding in protein sequences, and can visually reveal previously unknown structure. Fractal dimensions are good tools to measure sizes of complex, highly irregular geometric objects. In this paper, we convert each protein sequence into a high-dimensional vector by CGR algorithm and fractal dimension, and then predict protein solubility by these fractal features together with Chou's pseudo amino acid composition features and support vector machine (SVM). We extract and study six groups of features computed directly from the primary sequence, and each group is evaluated by the 10-fold cross-validation test. As the results of comparisons, the group of 445-dimensional vector gets the best results, the average accuracy is 0.8741 and average MCC is 0.7358. The resulting predictor is also compared with existing methods and shows significant improvement.     

同型半胱氨酸对心肌细胞的损伤作用及其信号转导机制探讨

目的：观察同型半胱氨酸（homocysteine,HCY)对心肌细胞的损伤作用,探讨该作用发生的信号转导机制及其关键调控环节。方法：分离培养Wistar乳鼠心肌细胞,经HCY作用后,以台盼蓝排斥实验测定细胞存活率,TUNEL法和流式细胞仪测定细胞凋亡率,免疫印迹法测定心肌细胞ERK2蛋白磷酸化水平,阻滞电泳法测定细胞NF－κB活化水平。结果：作用后,心肌细胞存活率显著降低,存活率降低程度与HCY的作用浓度、作用时间具有明确的剂量－效应关系及时间－效应关系;在10^-3mol/L HCY作用下,心肌细胞凋亡率升高,于4h达峰值,为7．56％;10^-3,10^-4、10^-5mol/L HCY均可抑制心肌细胞ERK2磷酸化,其中10^-3mol/L HCY作用于心肌细胞后,ERYK2蛋白磷酸化水平呈现迅速而明显的降低,4h降至对照组的3．04％（P＜0．01）;不同浓度HCY均明显阻抑NF－κB的活化。结论：HCY具有明显心肌细胞损伤作用,对心肌细胞凋亡的诱导是HCY心肌细胞损伤作用的形式之一;HCY可影响心肌细胞信号转导通路ERK,通过对转录因子NF－κB的活化抑制,导致心肌细胞损伤。     

Identification of <Emphasis Type="Italic">Escherichia coli</Emphasis> host cell for high plasmid stability and improved production of antihuman ovarian carcinoma × antihuman CD3 single-chain bispecific antibody

To improve the plasmid stability during the production of antihuman ovarian carcinoma × antihuman CD3 single-chain bispecific antibody (AhOC×AhCD3), the Escherichia coli BL21(DE3) host cell was optimized serially. Firstly, an isogenic recombination-deficient (recA ⁻) derivative of BL21(DE3), namely BLR(DE3), was used as host instead of BL21(DE3). Although the segregational plasmid stability was greatly improved, AhOC×AhCD3 yield was not improved due to the severe growth inhibition of plasmid-bearing BLR(DE3) cells and the competitive plasmid instability after induction. Secondly, a mutant BLR(DE3), namely BLRM(DE3), was screened by using LB agar plates plus ampicillin and isopropyl-β-d-thiogalactopyranoside. Using this new host, growth inhibition of recombinant cells after induction was eliminated, and plasmids could be stably maintained even after long-time induction in a nonselective medium. At last, about 1.2 g/l AhOC×AhCD3, which was about thrice as much as those of recombinant BL21(DE3) and BLR(DE3) strains, was yielded.     

Determination of the trichothecene mycotoxin chemotypes and associated geographical distribution and phylogenetic species of the Fusarium graminearum clade from China

A large number of isolates from the Fusarium graminearum clade representing all regions in China with a known history of Fusarium head blight (FHB) epidemics in wheat were assayed using PCR to ascertain their trichothecene mycotoxin chemotypes and associated phylogenetic species and geographical distribution. Of the 299 isolates assayed, 231 are from F. asiaticum species lineage 6, which produce deoxynivalenol and 3-acetyldeoxynivalenol (3-AcDON); deoxynivalenol and 15-acetyldeoxynivalenol (15-AcDON); and nivalenol and 4-acetylnivalenol (NIV) mycotoxins, with 3-AcDON being the predominant chemotype. Ninety-five percent of this species originated from the warmer regions where the annual average temperatures were above 15 °C, based on the climate data of 30 y during 1970–1999. However, 68 isolates within F. graminearum species lineage 7 consisted only of 15-AcDON producers, 59 % of which were from the cooler regions where the annual average temperatures were 15 °C or lower. Identification of a new subpopulation of 15-AcDON producers revealed a molecular distinction between F. graminearum and F. asiaticum that produce 15-AcDON. An 11-bp repeat is present in F. graminearum within their Tri7 gene sequences but is absent in F. asiaticum, which could be directly used for differentiating the two phylogenetic species of the F. graminearum clade.     

盐度对早期链霉菌产生二甲基异莰醇和土臭味素的影响

天津是中国北方重要的渔业生产基地,2006年全市水产养殖面积430 km2,水产品总产量35.5万吨,其中养殖产量30万吨,渔业产值40亿元。天津养鱼池水盐度普遍在2-5,属于寡盐水鱼池,但在该地区采取高密度精养模式生产鱼类普遍存在土腥异味,降低了水产品食用价值和养殖效益。       

菜豆种质形态及等位酶标记的研究

收集了黑龙江省43 份栽培品种, 国际热带农业中心13 份半野生品种, 波兰4 份矮生品种共60 份菜豆品种资源, 测定其植物学、生物学性状, 采用标准差标准化方法, 计算各材料间的欧氏距离, 其范围为0.110~0.985;从等位酶标记上进行了10 个酶系统检测, 共获得25 个位点, 多态位点比率为0.16, 其平均遗传距离为0.056 8 。根据计算所得60 份材料间的遗传相似度, 开展形态标记亲缘关系系统聚类图, 将其分为两大类, 即矮生种为一类, 蔓生种及半野生种合为一类。采用平均距离法, 将等位酶标记聚成8 大类, 其中蔓生种占5 类, 矮生种2 类, 半野生种2 类, 说明等位酶标记较具体, 且蔓生种遗传距离较远, 可作为育种材料储备种质资源。     

莎草科薹草属黑穗薹草组的植物地理学讨论

根据黑穗薹草组植物的外部形态、细胞染色体特征与地理分布之间的关系,结合地质历史事件推测了黑穗薹草组Sect.Racemosae G.Don.的起源、进化和迁移等问题。推测黑穗薹草组可能在早第三纪的始新世起源于我国的喜马拉雅-横断山地区;可能的迁移路径为：由起源中心向北部迁移至欧洲、中亚、俄罗斯西伯利亚地区,并通过格陵兰岛和白令陆桥到达北美洲地区;经过第四纪冰川后,一些分布于北美洲的物种又通过白令陆桥回迁到亚洲东部的俄罗斯远东地区,最终形成该组植物的现代分布格局。     

LncRNA SNHG14 aggravates invasion and migration as ceRNA via regulating miR-656-3p/SIRT5 pathway in hepatocellular carcinoma

Molecular and Cellular Biochemistry - The present study aimed to estimate the effects of high-protein diet (PD)—isolated whey protein and omega-3 fatty acids—docosahexaenoic and...     

Impact of prophylactic/preemptive donor lymphocyte infusion and intensified conditioning for relapsed/refractory leukemia: a real-world study

Prophylactic/preemptive donor lymphocyte infusion(p/pDLI) and intensified conditioning have shown promising results in experimental studies of refractory/relapsed acute leukemia(RRAL), but real-world data remain scarce. We conducted a multicenter, population-based analysis of 932 consecutive patients. The three-year leukemia-free survival(LFS) rates were 56% for patients receiving both p/pDLI and intensified myeloablative conditioning(MAC)(intenseMAC) and 30% for those who received neither therapy per landmark analysis. Multivariable analyses were run separately for acute myeloid leukemia(AML)and acute lymphoblastic leukemia(ALL), and p/pDLI treatment was linked to significantly higher LFS than non-DLI for both AML and ALL patients without increasing the nonrelapse mortality. IntenseMAC was associated with significantly lower relapse and higher LFS than nonintensified MAC despite higher nonrelapse mortality rates in ALL, while there was no impact of intenseMAC observed in AML. p/pDLI achieved superior outcomes in both matched-sibling donor(MSD) and haploidentical donor transplantation, while intenseMAC only influenced MSD outcomes. Data suggest that RRAL patients receiving "total therapy" by way of p/pDLI and intensified conditioning treatment have an improved chance for LFS, with p/pDLI being safer with a more extensive impact relative to intenseMAC. Patients with RRAL can tolerate both interventions and achieve a reasonable outcome.