Crosstalk between Growth and Osmoregulation of GHRH-SST-GH-IGF Axis in Triploid Rainbow Trout (Oncorhynchus mykiss)

Smolting is an important development stage of salmonid, and an energy trade-off occurs between osmotic regulation and growth during smolting in rainbow trout (Oncorhynchus mykiss). Growth hormone releasing hormone, somatostatin, growth hormone and insulin-like growth factor (GHRH-SST-GH-IGF) axis exhibit pleiotropic effects in regulating growth and osmotic adaptation. Due to salmonid specific genome duplication, increased paralogs are identified in the ghrh-sst-gh-igf axis, however, their physiology in modulating osmoregulation has yet to be investigated. In this study, seven sst genes (sst1a, sst1b, sst2, sst3a, sst3b, sst5, sst6) were identified in trout. We further investigated the ghrh-sst-gh-igf axis of diploid and triploid trout in response to seawater challenge. Kidney sst (sst1b, sst2, sst5) and sstr (sstr1b1, sstr5a, sstr5b) expressions were changed (more than 2-fold increase (except for sstr5a with 1.99-fold increase) or less than 0.5-fold decrease) due to osmoregulation, suggesting a pleiotropic physiology of SSTs in modulating growth and smoltification. Triploid trout showed significantly down-regulated brain sstr1b1 and igfbp2a1 (p < 0.05), while diploid trout showed up-regulated brain igfbp1a1 (~2.61-fold, p = 0.057) and igfbp2a subtypes (~1.38-fold, p < 0.05), suggesting triploid trout exhibited a better acclimation to the seawater environment. The triploid trout showed up-regulated kidney igfbp5a subtypes (~6.62 and 7.25-fold, p = 0.099 and 0.078) and significantly down-regulated igfbp5b2 (~0.37-fold, p < 0.05), showing a conserved physiology of teleost IGFBP5a in regulating osmoregulation. The IGFBP6 subtypes are involved in energy and nutritional regulation. Distinctive igfbp6 subtypes patterns (p < 0.05) potentially indicated trout triggered energy redistribution in brain and kidney during osmoregulatory regulation. In conclusion, we showed that the GHRH-SST-GH-IGF axis exhibited pleiotropic effects in regulating growth and osmoregulatory regulation during trout smolting, which might provide new insights into seawater aquaculture of salmonid species.     

Early Expression of Tet1 and Tet2 in Mouse Zygotes Altered DNA Methylation Status and Affected Embryonic Development

Ten-eleven translocation (Tet) dioxygenases can induce DNA demethylation by catalyzing 5-methylcytosine(5mC) to 5-hydroxymethylcytosine(5hmC), and play important roles during mammalian development. In mouse, Tet1 and Tet2 are not expressed in pronucleus-staged embryos and are not involved in the genomic demethylation of early zygotes. Here, we investigated the influence of Tet1 and Tet2 on methylation of parental genomes by ectopically expressing Tet1 and Tet2 in zygotes. Immunofluorescence staining showed a marked 5hmC increase in the maternal pronucleus after injection of Tet1 or Tet2 mRNA into zygotes. Whole-genome bisulfite sequencing further revealed that Tet2 greatly enhanced the global demethylation of both parental genomes, while Tet1 only promoted the paternal demethylation. Tet1 and Tet2 overexpression altered the DNA methylation across genomes, including various genic elements and germline-specific differently methylated regions. Tet2 exhibited overall stronger demethylation activity than Tet1. Either Tet1 or Tet2 overexpression impaired preimplantation embryonic development. These results demonstrated that early expression of Tet1 and Tet2 could substantially alter the zygotic methylation landscape and damage embryonic development. These findings provide new insights into understanding the function of Tet dioxygenases and the mechanism of DNA methylation in relation to embryogenesis.     

Low-latency and low-overhead encoder ASIC in the ATLAS LAr calorimeter trigger upgrade

In this article, an encoder Application Specific Integrated Circuit (ASIC) for high-speed serial data transmission is presented. The ASIC implements a low-latency and low-overhead line code and is fabricated with a commercial 0.25-µm Silicon-on-Sapphire CMOS technology. The ASIC operates at 640 MHz with a latency of no greater than 6.25 ns and the overhead of 14.3%. The encoder will be integrated with a serialiser and will be used in the A Toroidal LHC ApparatuS Liquid Argon (LAr) calorimeter Phase-I trigger upgrade.     

Fermi-Level Pinning in Nanocrystal Memories

The nanocrystal (NC) work-function engineering, which plays an important role on the NC memory characteristics such as memory window and retention time, were long regarded as a matter of choice on NC materials. In this letter, we report opposite polarities of charge storage in Au NC memories with different control oxides. The effective NC work function is found to be not only a bulk property of the NC, but also governed by the interface with surrounding dielectric, as a result of the Fermi-level pinning. By replacing Au NCs with C₆₀ molecules, we also show the pinning effect generally exists at quantum-dot-based devices with high density of interface states. This fundamental interface property should be taken into account in the selection of NC and dielectric materials for the NC memory optimization     

In situ synchrotron X-ray diffraction analysis of deformation behavior of a Nb/NiTi composite for biomedical applications

The deformation behavior involved in Nb/NiTi composite for biomedical applications within a large macroscopic strain range was investigated by tensile loading-unloading test and in situ synchrotron X-ray diffraction(SXRD).Experimental results show that during loading,the Nb/NiTi composite experiences the elastic elongation of B2-NiTi austenitic,B19'-NiTi martensitic and β-Nb phases,B2→ B19' stress-induced martensitic(SIM) transformation and tensile plastic deformation of β-Nb phase.During unloading,the deformation behavior involved in Nb/NiTi composite includes the elastic recovery of B2-NiTi austenitic,B19'-NiTi martensitic and β-Nb phases,reverse phase transformation B19'→B2 and compressive deformation of p-Nb phase.The martensitic transformation in this composite is almost reversible and occurs in a localized manner.These results might contribute to a comprehensive understanding of the deformation mechanism involved in Nb/NiTi composite and shed some light on design and development of novel composites with a combination of good biocompatibility and excellent superelasticity for biomedical applications.     

Sogatella furcifera Saliva Mucin-like Protein Is Required for Feeding and Induces Rice Defences

The white-backed planthopper (WBPH), Sogatella furcifera, is one of the most important piercing-sucking pests of rice (Oryza sativa) in Asia. Mucin-like salivary protein (SFMLP) is highly expressed in the salivary glands of WBPH, which plays an important role in WBPH feeding. In this study, WBPH injected with dsSFMLP had difficulty in sucking phloem sap from rice plants, which significantly reduced their food intake, weight, and survival. In contrast, the knockdown of the SFMLP gene had only a marginal effect on the survival of WBPH fed an artificial diet. Further studies showed that silencing SFMLP resulted in the short and single-branched salivary sheaths secretion and less formation of salivary flanges in rice. These data suggest that SFMLP is involved in the formation of the salivary sheath and is essential for feeding in WBPH. Overexpression of the SFMLP gene in rice plants promoted the feeding of WBPH, whereas silencing the gene in rice plants significantly decreased WBPH performance. Additionally, it was found that overexpression of SFMLP in rice plants elicited the signalling pathway of SA (salicylic acid) while suppressing JA (jasmonic acid); in contrast, silencing of the SFMLP gene in rice plants showed the opposite results. This study clarified the function of SFMLP in WBPH feeding as well as mediating rice defences.     

氧弹式量热计测定燃烧焓实验操作条件的改进

GR-3500型氧弹式量热计做燃烧焓的测定实验时间长,操作难度大,实验一次性成功率低.通过放宽对实验过程中夹层与量热容器的水温差值要求,实验结果表明夹层水温高于量热容器水温的0.5～3.0℃都是可行的,这样便于学生调节水温,缩短实验时间,取得良好的实验效果.     

抗氧剂1010的晶型分析

利用差示扫描量热分析(DSC)、红外光谱(IR)、粉末X射线衍射(XRD)等手段对抗氧剂1010样品进行了晶体结构分析。不同方法各有特点,分析结果应是几种方法的相互印证与归纳统一。     

透明聚丙烯EP2X32G结晶性能研究

通过差示扫描量热仪和广角X光衍射等分析方法,研究EP2X32G及其基料的结晶性能。结果表明,EP2X32G及其基料中存在α和γ两种晶型。     

原油储罐保温节能计算

联合站内一次沉降罐通常是不保温的,人们主要是从流体的热力条件去考虑,认为一次沉降罐含水较高,不进行保温对沉降效果及原油的流动也没有多大影响。但是如果从能量损耗的角度考虑,一次沉降罐不进行保温既降低了沉降温度,又浪费了燃料。本文通过对大罐的油罐保温与散热量、热平衡及节能分析,得出了对一次罐进行保温是必要的结论。采用的保温层厚度可为40mm和80mm的岩棉和塑料。在设计时应根据实际情况对大罐保温进行计算与效益分析,以达到节能降耗的目的。