Expression, purification, and crystallization of the Escherichia coli selenomethionyl beta-ketoacyl-acyl carrier protein synthase III

Bacterial beta-ketoacyl-acyl carrier protein (ACP) synthase III (KAS III, also called FabH) catalyzes the condensation and transacylation of acetyl-CoA with malonyl-ACP. In order to understand the mode of enzyme/substrate interaction and design small molecule inhibitors, we have expressed, purified, and crystallized a selenomethionyl-derivative of E. coli KAS III. Several lines of evidence confirmed that purified selenomethionyl KAS III was homogenous, stably folded, and enzymatically active. Dynamic light scattering, size exclusion chromatography, and mass spectrometry results indicated that selenomethionyl KAS III is a noncovalent homodimer. Diffraction quality crystals of selenomethionyl KAS III/acetyl-CoA complex, which grew overnight to a size of 0.2 mm(3), belonged to the tetragonal space group P4(1)2(1)2.     

新疆麦田主要蚜虫的生态位

利用生态位理论,对新疆塔城、伊犁两地区麦田的麦双尾蚜Diuraphis noxia (Mordvilko)、麦二叉蚜Shizaphis graminum (Rondani)、麦长管蚜Sitobion avenae (F.)和禾谷缢管蚜Rhopalosiphum padi (L.)等4种麦蚜生态位宽度和重叠度进行了估测和分析。在塔城麦田麦双尾蚜时间生态位宽度最大,麦双尾蚜和麦二叉蚜时间生态位重叠最大,竞争激烈。伊犁麦田禾谷缢管蚜时间生态位宽度最大,麦二叉蚜在空间生态位和时 空二维生态位上均占有明显的优势,麦长管蚜和麦双尾蚜的时间生态位重叠最大,麦长管蚜和麦二叉蚜在空间生态位和时 空生态位重叠最大。     

Improvements in the primary culture of neonate rat myocardial cells by study of the mechanism of endoplasmic reticulum stress

We previously found that endoplasmic reticulum stress (ERS) might be exhibited in the conventional protocol of the primary culture of neonate rat myocardial cells (NRMCs) and that the high glucose concentration (25 mmol/L) in the culture medium might be the cause. Here, we investigated if the high concentration of glucose might influence ERS in myocardial cells during culture. GRP78 expression (ERS marker) was similar in groups with tunicamycin (TM) and without TM in high glucose cultured cells (p?>?0.01). Different glucose concentrations elicited different GRP78 expressions according to analyses of protein and RNA levels, which showed ERS in H/H groups. Finally, we found that GRP78 expression was higher in TM groups compared with M/M groups (p?<?0.01). The conventional high-glucose culture media during primary culture of NRMCs induced ERS. We propose that medium-glucose culture media should be used and describe an improved protocol for the primary culture of NRMCs.     

Dynamic metagenome-scale metabolic modeling of a yogurt bacterial community

Genome-scale metabolic models and flux balance analysis (FBA) have been extensively used for modeling and designing bacterial fermentation. However, FBA-based metabolic models that accurately simulate the dynamics of coculture are still rare, especially for lactic acid bacteria used in yogurt fermentation. To investigate metabolic interactions in yogurt starter culture of Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus, this study built a dynamic metagenome-scale metabolic model which integrated constrained proteome allocation. The accuracy of the model was evaluated by comparing predicted bacterial growth, consumption of lactose and production of lactic acid with reference experimental data. The model was then used to predict the impact of different initial bacterial inoculation ratios on acidification. The dynamic simulation demonstrated the mutual dependence of S. thermophilus and L. d. bulgaricus during the yogurt fermentation process. As the first dynamic metabolic model of the yogurt bacterial community, it provided a foundation for the computer-aided process design and control of the production of fermented dairy products.     

LncRNA ZNF667-AS1靶向miR-31-5p对食管癌细胞增殖、迁移和凋亡的机制研究

目的 探究长链非编码RNA(lncRNA)ZNF667-AS1通过靶向miR-31-5p对食管癌细胞增殖和迁移的影响及潜在的机制.方法 采用实时荧光定量PCR(qPCR)技术检测ZNF667-AS1在食管癌细胞Eca109、EC1、TE1和正常食管上皮细胞Het-1A的表达水平,并选择表达差异最大的细胞株进行后续实验....     

Effect of Alkylsilyl Side‐Chain Structure on Photovoltaic Properties of Conjugated Polymer Donors

Side‐chain engineering is an important strategy for optimizing photovoltaic properties of organic photovoltaic materials. In this work, the effect of alkylsilyl side‐chain structure on the photovoltaic properties of medium bandgap conjugated polymer donors is studied by synthesizing four new polymers J70 , J72 , J73 , and J74 on the basis of highly efficient polymer donor J71 by changing alkyl substituents of the alkylsilyl side chains of the polymers. And the photovoltaic properties of the five polymers are studied by fabricating polymer solar cells (PSCs) with the polymers as donor and an n‐type organic semiconductor (n‐OS) m‐ITIC as acceptor. It is found that the shorter and linear alkylsilyl side chain could afford ordered molecular packing, stronger absorption coefficient, higher charge carrier mobility, thus results in higher J_sc and fill factor values in the corresponding PSCs. While the polymers with longer or branched alkyl substituents in the trialkylsilyl group show lower‐lying highest occupied molecular orbital energy levels which leads to higher V_oc of the PSCs. The PSCs based on J70 :m‐ITIC and J71 :m‐ITIC achieve power conversion efficiency (PCE) of 11.62 and 12.05%, respectively, which are among the top values of the PSCs reported in the literatures so far.     

Ternary Organic Solar Cells With 12.8% Efficiency Using Two Nonfullerene Acceptors With Complementary Absorptions

A new small‐molecule acceptor (2,9‐bis(2‐methylene‐(3(1,1‐dicyanomethylene)benz[f]indanone))7,12‐dihydro‐(4,4,10,10‐tetrakis(4‐hexylphenyl)‐5,11‐diocthylthieno[3′,2′:4,5]cyclopenta[1,2‐b]thieno[2″,3″:3′,4′]cyclopenta[1′,2′:4,5]thieno[2,3‐f][1]benzothiophene) (NNBDT) based on naphthyl‐fused indanone ending units is reported. This molecule shows a narrow optical bandgap of 1.43 eV and effective absorption in the range of 700–870 nm. The devices based on poly[(2,6‐(4,8‐bis(5‐(2‐ethylhexyl)thiophen‐2‐yl)‐benzo[1,2‐b:4,5‐b′]dithiophene))‐alt‐(5,5‐(1′,3′‐di‐2‐thienyl‐5′,7′‐bis(2‐ethylhexyl)benzo[1′,2′‐c:4′,5′‐c′]dithiophene‐4,8‐dione))] (PBDB‐T):NNBDT yield a power conversion efficiency of 11.7% with a low energy loss of 0.55 eV and a high fill factor (FF) of 71.7%. Another acceptor (2,9‐bis(2‐methylene‐(3(1,1‐dicyanomethylene)benz[f]indanone))7,12‐dihydro‐4,4,7,7,12,12‐hexaoctyl‐4H‐cyclopenta[2″,1″:5,6;3″,4″:5′,6′]diindeno[1,2‐b:1′,2′‐b′]dithiophene (FDNCTF) is introduced as the third component to fabricate ternary devices. The two acceptors (NNBDT and FDNCTF) possess complementary absorption, same molecular orientation, and well‐miscible behavior. It is found that there exists a nonradiative energy transfer process from FDNCTF to NNBDT. The fullerene‐free ternary cells based on PBDB‐T:NNBDT:FDNCTF achieve a high efficiency of 12.8% with an improved short circuit current near 20 mA cm^?2 in contrast to the binary devices. The result represents the best performance for fullerene‐free ternary solar cells reported to date and highlights the potential of ternary solar cells.     

Efficacy Comparison of Six Chemotherapeutic Combinations for Osteosarcoma and Ewing's Sarcoma Treatment: A Network Meta‐Analysis

This study aimed to address the insufficiency of traditional meta‐analysis and provide improved guidelines for the clinical practice of osteosarcoma treatment. The heterogeneity of the fixed‐effect model was calculated, and when necessary, a random‐effect model was adopted. Furthermore, the direct and indirect evidence was pooled together and exhibited in the forest plot and slash table. The surface under the cumulative ranking curve (SUCRA) value was also measured to rank each intervention. Finally, heat plot was introduced to demonstrate the contribution of each intervention and the inconsistency between direct and indirect comparisons. This network meta‐analysis included 32 trials, involving a total of 5,626 subjects reported by 28 articles. All the treatments were classified into six chemotherapeutic combinations: dual agent with or without ifosfamide (IFO), multi‐agent with or without IFO, and dual agent or multi‐agent with IFO and etoposide. For the primary outcomes, both overall survival (OS) and event‐free survival (EFS) rates were considered. The multi‐agent integrated with IFO and etoposide showed an optimal performance for 5‐year OS, 10‐year OS, 3‐year EFS, 5‐year EFS, and 10‐year EFS when compared with placebo. The SUCRA value of this treatment was also the highest of these six interventions. However, multi‐drug with IFO alone had the highest SUCRA value of 0.652 and 0.516 when it came to relapse and lung‐metastasis. It was efficient to some extent, but no significant difference was observed in both outcomes. Chemotherapy, applied as induction or adjuvant treatment with radiation therapy or surgery, is able to increase the survival rate of patients, especially by combining multi‐drug with IFO and etoposide, which demonstrated the best performance in both OS and EFS. As for relapse and the lung‐metastasis, multiple agents with IFO alone seemed to have the optimal efficiency, although no significant difference was observed here. J. Cell. Biochem. 119: 250–259, 2018. © 2017 Wiley Periodicals, Inc.     

<Emphasis Type="Italic">Flavobacterium zaozhuangense</Emphasis> sp. nov., a new member of the family <Emphasis Type="Italic">Flavobacteriaceae</Emphasis>, isolated from metolachlor-contaminated soil

Strain ZZ-8^T, a Gram-negative, aerobic, non-spore-forming, non-motile, yellow-pigmented, rod-shaped bacterium, was isolated from metolachlor-contaminated soil in China. The taxonomic position was investigated using a polyphasic approach. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain ZZ-8^T is a member of the genus Flavobacterium and shows high sequence similarity to Flavobacterium humicola UCM-46^T (97.2%) and Flavobacterium pedocola UCM-R36^T (97.1%), and lower (<?97%) sequence similarity to other known Flavobacterium species. Chemotaxonomic analysis revealed that strain ZZ-8^T possessed MK-6 as the major respiratory quinone; and iso-C_15:0 (28.5%), summed feature 9 (iso-C_17:1 w9c/C_16:0 10-methyl, 22.9%), iso-C_17:0 3-OH (17.0%), iso-C_15:0 3-OH (8.9%), iso-C_15:1 G (8.6%) and summed feature 3 (C_16:1 w7c/C_16:1 w6c, 5.7%) as the predominant fatty acids. The polar lipids of strain ZZ-8^T were determined to be lipids, a glycolipid, aminolipids and phosphatidylethanolamine. Strain ZZ-8^T showed low DNA–DNA relatedness with F. pedocola UCM-R36^T (43.23?±?4.1%) and F. humicola UCM-46^T (29.17?±?3.8%). The DNA G+C content was 43.3 mol%. Based on the phylogenetic and phenotypic characteristics, chemotaxonomic data and DNA–DNA hybridization, strain ZZ-8^T is considered a novel species of the genus Flavobacterium, for which the name Flavobacterium zaozhuangense sp. nov. (type strain ZZ-8^T?=?KCTC 62315 ^T?=?CCTCC AB 2017243^T) is proposed.