Erratum to: Overdose the addiction—A new strategy to ablate cancer cells

正The figure legend mistakenly referred to Reference 3 instead of Reference 1.It should read:"Adapted from Hu et al.[1]with permission from the authors."The author apologizes for any inconvenience it might have caused.     

退耕还林还草工程对陕北地区生态系统服务价值时空演变的影响

基于陕北地区1990、2000、2015年土地利用数据，运用单位面积生态系统价值当量因子法、格网法、探索性空间数据法（ESDA），分析了退耕还林还草工程实施前后生态系统服务价值（ESV）的空间分布和演化规律，探讨了退耕还林还草工程对ESV的影响。结果表明：（1）陕北地区退耕还林还草工程实施效果显著，工程实施后共有297066.15 hm2耕地转化为林地和草地，林草覆盖率由57.33%增长至60.50%。（2）退耕还林还草工程使得陕北地区ESV得到了显著提升。25年间陕北地区ESV共增加了32.82亿元，ESV在工程实施后比工程实施前多增加了5.93亿元，增长主要源于退耕引起林地和草地面积的增加。（3）ESV空间分布上呈显著的“南高北低”分布格局，并表现出正向的集聚性和依存性，ESV热点区和冷点区集聚效果明显，热点区集聚与林地、草地的空间分布相吻合，冷点区集聚与未利用地、耕地和建设用地的空间分布相吻合。（4）受退耕还林还草工程影响，陕北地区中部中等等级和次高ESV分布区域逐渐增大、次热点区空间集聚性逐渐增强，北部次低等级和低等级ESV分布区域逐渐减少、冷点区空间集聚性逐渐减弱。整体而言，陕北地区土地利用类型转移和ESV的增减变化与推行退耕还林还草工程在时间上相呼应、在空间上相匹配，退耕还林还草工程实施使得陕北地区生态环境得到了有效改善，ESV得到了显著提升。     

LncRNA882 regulates leukemia inhibitory factor (LIF) by sponging miR-15b in the endometrial epithelium cells of dairy goat

Despite the fact that long noncoding RNAs (lncRNAs) play roles in almost all biological processes, little is known about their biological function in the endometrium during the formation of endometrial receptivity. In this study, a comprehensive analysis of lncRNAs in goat endometrial tissues on Day 5 (prereceptive endometrium, PE) and Day 15 (receptive endometrium, RE) of pregnancy was performed by using RNA-Seq. As a result, 668 differentially expressed lncRNAs (DELs) were found between the PE and RE. Further study showed that lncRNA882, regulated by estrogen (E2) and progestin (P4), could act as competing endogenous RNAs (ceRNAs) for miR-15b, which inhibited the expression of transforming growth factor-b-activated kinase 1 binding protein 3 (TAB3) and then indirectly regulated the level of leukemia inhibitory factor (LIF). This was helpful for the formation of endometrial receptivity in dairy goats. In conclusion, we elucidated the endometrium lncRNA profiles of PE and RE in dairy goats; lncRNA882 acted as a ceRNA for miR-15b and then indirectly regulated the level of LIF in goat endometrial epithelium cells. Thus, this study helped us to better understand the molecular regulation of endometrial receptivity in dairy goats.     

A Novel Endogenous Induction of ColE7 Expression in a csrA Mutant of Escherichia coli

Carbon storage regulator A (CsrA) is an important regulator that controls central metabolic pathways and a variety of physiological functions. We found that disruption of csrA in cells containing the ColE7 operon caused a 12-fold increase in colicin E7 production. Moreover, real-time RT-PCR demonstrated a decrease of around 50 % in the lexA mRNA of the csrA mutant. However, the cellular level of RecA protein and its mRNA were not significantly different from the wild type strain. Our results suggest that a novel induction mechanism might exist in E. coli that allows the expression of ColE7 operon in response to a metabolic shift. Proteomic analysis suggested that csrA deficient mutant may adapt PEP-glyoxylate cycle for energy production. Thus, the physiological changes in the csrA mutant may be similar to carbon source limitation for initiating the expression of ColE7 operon in response to stringent environmental conditions.     

Progressive Degradation of Crude Oil n-Alkanes Coupled to Methane Production under Mesophilic and Thermophilic Conditions

Although methanogenic degradation of hydrocarbons has become a well-known process, little is known about which crude oil tend to be degraded at different temperatures and how the microbial community is responded. In this study, we assessed the methanogenic crude oil degradation capacity of oily sludge microbes enriched from the Shengli oilfield under mesophilic and thermophilic conditions. The microbial communities were investigated by terminal restriction fragment length polymorphism (T-RFLP) analysis of 16S rRNA genes combined with cloning and sequencing. Enrichment incubation demonstrated the microbial oxidation of crude oil coupled to methane production at 35 and 55°C, which generated 3.7±0.3 and 2.8±0.3 mmol of methane per gram oil, respectively. Gas chromatography-mass spectrometry (GC-MS) analysis revealed that crude oil n-alkanes were obviously degraded, and high molecular weight n-alkanes were preferentially removed over relatively shorter-chain n-alkanes. Phylogenetic analysis revealed the concurrence of acetoclastic Methanosaeta and hydrogenotrophic methanogens but different methanogenic community structures under the two temperature conditions. Candidate divisions of JS1 and WWE 1, Proteobacteria (mainly consisting of Syntrophaceae, Desulfobacteraceae and Syntrophorhabdus) and Firmicutes (mainly consisting of Desulfotomaculum) were supposed to be involved with n-alkane degradation in the mesophilic conditions. By contrast, the different bacterial phylotypes affiliated with Caldisericales, “Shengli Cluster” and Synergistetes dominated the thermophilic consortium, which was most likely to be associated with thermophilic crude oil degradation. This study revealed that the oily sludge in Shengli oilfield harbors diverse uncultured microbes with great potential in methanogenic crude oil degradation over a wide temperature range, which extend our previous understanding of methanogenic degradation of crude oil alkanes.     

Myrothins A–F from Endophytic Fungus Myrothecium sp. BS-31 Harbored in Panax notoginseng

Endophytic fungi play important roles for host's stress tolerance including invasion by pathogenic microbes. Small molecules are common weapons in the microbe–microbe interactions. Panax notoginseng is a widely used traditional Chinese medicinal plant and harbors many endophytes, some exert functions against pathogens. Here, we report six new compounds named myrothins A–F ( 1 – 6 ) produced by Myrothecium sp. BS-31, an endophyte isolated from P. notoginseng, and their antifungal activities against pathogenic fungi causing host root-rot disease. Their structures were elucidated with analysis of spectroscopic data including 1D and 2D NMR, HR-ESI-MS. Myrothins B ( 2 ) and E ( 5 ) showed the weak activity against Fusarium oxysporum and Phoma herbarum, and myrothins F ( 6 ) showed weak activity against F. oxysporum.