Optimized Catalytic WS2–WO3 Heterostructure Design for Accelerated Polysulfide Conversion in Lithium–Sulfur Batteries

The lithium–sulfur (Li–S) battery is a next generation high energy density battery, but its practical application is hindered by the poor cycling stability derived from the severe shuttling of lithium polysulfides (LiPSs). Catalysis is a promising way to solve this problem, but the rational design of relevant catalysts is still hard to achieve. This paper reports the WS₂–WO₃ heterostructures prepared by in situ sulfurization of WO₃, and by controlling the sulfurization degree, the structure is controlled, which balances the trapping ability (by WO₃) and catalytic activity (by WS₂) toward LiPSs. As a result, the WS₂–WO₃ heterostructures effectively accelerate LiPS conversion and improve sulfur utilization. The Li–S battery with 5 wt% WS₂–WO₃ heterostructures as additives in the cathode shows an excellent rate performance and good cycling stability, revealing a 0.06% capacity decay each cycle over 500 cycles at 0.5 C. By building an interlayer with such heterostructure‐added graphenes, the battery with a high sulfur loading of 5 mg cm^?2 still shows a high capacity retention of 86.1% after 300 cycles at 0.5 C. This work provides a rational way to prepare the metal oxide–sulfide heterostructures with an optimized structure to enhance the performance of Li–S batteries.     

Profiling of dynamic changes in the microbial community during the soy sauce fermentation process

Soy sauce is a traditional condiment manufactured by natural inoculation and mixed culture fermentation. As is well known, it is the microbial community that plays an important role in the formation of its flavors. However, to date, its dynamic changes during the long period of fermentation process are still unclear, intensively constraining the improvement and control of the soy sauce quality. In this work, we revealed the dynamic changes of the microbial community by combining a cultured dependent method and a cultured independent method of polymerase chain reaction (PCR)-denaturing gradient gel electrophoresis. Results indicated that the two methods verified and complemented each other in profiling microbial community, and that significant dynamics of the microbial community existed during the fermentation process, especially the strong inhibition of the growth of most of the microbes when entering into the mash stage from the koji stage. In the analysis of bacterial community, Staphylococcus and Bacillus were found to be the dominant bacteria and detected in the whole fermentation process. Kurthia and Klebsiella began to appear in the koji stage and then fade away in the early stage of the mash fermentation. In the analysis of fungal community, Aspergillus sojae and Zygosaccharomyces rouxii were found to be the dominant fungi in the koji and mash fermentation, respectively. It was clearly shown that when A. sojae decreased and disappeared in the middle stage of the mash fermentation, Z. rouxii appeared and increased at the meantime. Aspergillus parasiticus, Trichosporon ovoides and Trichosporon asahii also appeared in the koji and the early period of the mash fermentation and disappeared thereafter. Similar to Z. rouxii, Millerozyma farinosa and Peronospora farinosa were also found spontaneously which appeared in the mid-late period of the mash fermentation. The principal component analysis suggested that the microbial community underwent significant changes in the early period of the fermentation and, thereafter, tended to the stabilization in the mid-late periods. This study gave us important clues to understand the fermentation process and can serve as a foundation for improving the quality of soy sauce in the future.     

Plasticity for colour adaptation in vertebrates explained by the evolution of the genes pomc,pmch and pmchl

Different camouflages work best with some background matching colour. Our understanding of the evolution of skin colour is based mainly on the genetics of pigmentation (“background matching”), with little known about the evolution of the neuroendocrine systems that facilitate “background adaptation” through colour phenotypic plasticity. To address the latter, we studied the evolution in vertebrates of three genes, pomc, pmch and pmchl, that code for α‐MSH and two melanin‐concentrating hormones (MCH and MCHL). These hormones induce either dispersion/aggregation or the synthesis of pigments. We find that α‐MSH is highly conserved during evolution, as is its role in dispersing/synthesizing pigments. Also conserved is the three‐exon pmch gene that encodes MCH, which participates in feeding behaviours. In contrast, pmchl (known previously as pmch), is a teleost‐specific intron‐less gene. Our data indicate that in zebrafish, pmchl‐expressing neurons extend axons to the pituitary, supportive of an MCHL hormonal role, whereas zebrafish and Xenopus pmch+ neurons send axons dorsally in the brain. The evolution of these genes and acquisition of hormonal status for MCHL explain different mechanisms used by vertebrates to background‐adapt.     

Abdominal and hip flexor muscle activation during various training exercises

 The purpose of this study was to provide objective information on the involvement of different abdominal and hip flexor muscles during various types of common training exercises used in rehabilitation and sport. Six healthy male subjects performed altogether 38 different static and dynamic training exercises – trunk and hip flexion sit-ups, with various combinations of leg position and support, and bi- and unilateral leg lifts. Myoelectric activity was recorded with surface electrodes from the rectus abdominis, obliquus externus, obliquus internus, rectus femoris, and sartorius muscles and with indwelling fine-wire electrodes from the iliacus muscle. The mean electromyogram amplitude, normalised to the highest observed value, was compared between static and dynamic exercises separately. The hip flexors were highly activated only in exercises involving hip flexion, either lifting the whole upper body or the legs. In contrast, the abdominal muscles showed marked activation both during trunk and hip flexion sit-ups. In hip flexion sit-ups, flexed and supported legs increased hip flexor activation, whereas such modifications did not generally alter the activation level of the abdominals. Bilateral, but not unilateral, leg lifts required activation of abdominal muscles. In trunk flexion sit-ups an increased activation of the abdominal muscles was observed with increased flexion angle, whereas the opposite was true for hip flexion sit-ups. Bilateral leg lifts resulted in higher activity levels than hip flexion sit-ups for the iliacus and sartorius muscles, while the opposite was true for rectus femoris muscles. These data could serve as a basis for improving the design and specificity of test and training exercises. Accepted: 12 August 1996     

人脂素基因LIPIN1在酵母中的异源表达及细胞功能分析

脂类代谢调控是维持生物体能量平衡的重要环节,脂类代谢调控的紊乱与肥胖症、糖尿病和高血压等疾病密切相关。脂素基因三LIPIN1是诱导脂肪细胞分化、调控脂类合成的关键基因．其编码的磷脂磷酸酶（phosphatidate phosphatase,PAP）在人体三酰甘油合成中起关键作用,是维持人体脂类平衡的重要保障。此外,该基因还作为重要的转录辅激活因子参与多种生长及营养代谢调控。多种生物中均有类似功能的基因被发现,暗示了其功能的多样性及物种间的保守性。该文利用酿酒酵母在脂类代谢研究中性状易于表征、同源基因剧刖功能明确的优势,通过同源重组技术构建脂素缺陷型酵母,探索脂素基因在维持酵母正常生长及脂类合成中的重要作用,并通过功能互补及生物信息学技术对比分析了人源LIPIN1基因与酵母PdH1基因编码蛋白在结构和功能上的保守性,为脂素基因LIPIN1的细胞功能研究提供基础数据。     

High-quality genome assembly of an important biodiesel plant,Euphorbia lathyris L

Caper spurge, Euphorbia lathyris L., is an important energy crop and medicinal crop. Here, we generated a high-quality, chromosome-level genome assembly of caper spurge using Oxford Nanopore sequencing, Illumina sequencing, and Hi-C technology. The final genome assembly was ∼988.9 Mb in size, 99.8% of which could be grouped into 10 pseudochromosomes, with contig and scaffold N50 values of 32.6 and 95.7 Mb, respectively. A total of 651.4 Mb repetitive sequences and 36,342 protein-coding genes were predicted in the genome assembly. Comparative genomic analysis showed that caper spurge and castor bean clustered together. We found that no independent whole-genome duplication event had occurred in caper spurge after its split from the castor bean, and recent substantial amplification of long terminal repeat retrotransposons has contributed significantly to its genome expansion. Furthermore, based on gene homology searching, we identified a number of candidate genes involved in the biosynthesis of fatty acids and triacylglycerols. The reference genome presented here will be highly useful for the further study of the genetics, genomics, and breeding of this high-value crop, as well as for evolutionary studies of spurge family and angiosperms.     

MEK/ERK signaling contributes to the maintenance of human embryonic stem cell self-renewal

MEK/ERK signaling plays a crucial role in a diverse set of cellular functions including cell proliferation, differentiation and survival, and recently has been reported to negatively regulate mouse embryonic stem cell (mESC) self-renewal by antagonizing STAT3 activity. However, its role in human ESCs (hESCs) remains unclear. Here we investigated the functions of MEK/ERK in controlling hESC activity. We demonstrated that MEK/ERK kinases were targets of fibroblast growth factor (FGF) pathway in hESCs. Surprisingly, we found that, in contrast to mESCs, high basal MEK/ERK activity was required for maintaining hESCs in an undifferentiated state. Inhibition of MEK/ERK activity by specific MEK inhibitors PD98059 and U0126, or by RNA interference, rapidly caused the loss of self-renewal capacity. We also showed that MEK/ERK signaling cooperated with phosphoinositide 3-kinase (PI3K)/AKT signaling in maintaining hESC pluripotency. However, MEK/ERK signaling had little or no effect on regulating hESC proliferation and survival, in contrast to PI3K/AKT signaling. Taken together, these findings reveal the unique and crucial role of MEK/ERK signaling in the determination of hESC cell fate and expand our understanding of the molecular mechanisms behind the FGF pathway maintenance of hESC pluripotency. Importantly, these data make evident the striking differences in the control of self-renewal between hESCs and mESCs.     

Vertically Aligned Lithiophilic CuO Nanosheets on a Cu Collector to Stabilize Lithium Deposition for Lithium Metal Batteries

Uncontrollable dendrite growth hinders the direct use of a lithium metal anode in batteries, even though it has the highest energy density of all anode materials. Achieving uniform lithium deposition is the key to solving this problem, but it is hard to be realized on a planar electrode surface. In this study, a thin lithiophilic layer consisting of vertically aligned CuO nanosheets directly grown on a planar Cu current collector is prepared by a simple wet chemical reaction. The lithiophilic nature of the CuO nanosheets reduces the polarization of the electrode, ensuring uniform Li nucleation and continuous smooth Li plating, which is difficult to realize on the normally used lithiophobic Cu current collector surface. The integration of the grown CuO arrays and the Cu current collector guarantees good electron transfer, and moreover, the vertically aligned channels between the CuO nanosheets guarantee fast ion diffusion and reduce the local current density. As a result, a high Columbic efficiency of 94% for 180 cycles at a current density of 1 mA cm^?2 and a prolonged lifespan of a symmetrical cell (700 h at 0.5 mA cm^?2) can be easily achieved, showing a simple but effective way to realize Li metal‐based anode stabilization.     

Synergistic effects of plant growth retardants and IBA on the formation of adventitious roots in hypocotyl cuttings of mung bean

The synergistic effect of plant growth retardants, such as daminozide, paclobutrazol and triadimefon, and of indole-3-butyric acid (IBA) on the formation of adventitious roots in hypocotyl cuttings of mung bean was studied. The three retardants and IBA all stimulated adventitious root growth, but IBA was the most effective. However, mixtures of the retardants with IBA have proven generally more effective than IBA alone in promoting adventitious root formation. When IBA was applied to the hypocotyls one day after cutting preparation followed by the growth retardant on the second day, there were even more adventitious roots produced than if applied in the reverse order. The effectiveness of the treatments were in the order, IBA followed by growth retardant, IBA + growth retardant together, and IBA alone.Abbreviations IBA indole-3-butyric acid - GA gibberellin     

分布式模型在流域蒸散模拟中的应用与验证

根据四川杂谷脑河流域上游地区1989～2000年气象站常规观测数据,应用分布式模型方法,考虑流域的空间异质性及时空变异性,选择离散单元格尺度为500 m,时间步长为1 d,采用Penman-Monteith公式的改进形式,估算流域多年平均潜在蒸散量的时空分布;结合流域下垫面特点,估算逐日实际蒸散量的时空分布;并将模型模拟的多年平均值与研究区同期水量平衡法计算结果相比,相对误差为+3.47%且时空分布合理.为流域分布式降雨-径流模型提供了可靠的实际蒸散量模拟方法.