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Very long chain polyunsaturated fatty acids (VLC-PUFAs) are unique fatty acids in tissues of mammals such as retina and testis, and the key enzyme of its biosynthesis is very long chain fatty acid elongase 4 (Elovl4). Development of an animal model of tissue-specific knockout of

Essential fatty acids are those that could not be synthesized by the body itself but crucial for health and life. Studies have shown that ω-3 fatty acids may facilitate human physiological functions. Mammals lack ω-3 desaturase gene, and the Δ15 fatty acid desaturase (Δ15 Des) from

BackgroundIt has been reported that there are more than ten antimicrobial peptides (AMPs) belonging to the cecropin family inMusca domestica; however, few of them have been identified, and the functions of the other molecules are poorly understood.MethodsSequences of theM. domesticacecropin family of genes were cloned from cDNA template, which was reverse-transcribed from total mRNA isolated from third-instar larvae ofM. domesticathat were challenged with pathogens. Sequence analysis was performed using DNAMAN comprehensive analysis software, and a molecular phylogenetic tree of the cecropin family was constructed using the Neighbour-Joining method in MEGA v.5.0 according to the mature peptide sequences. Antibacterial activity of the syntheticM. domesticacecropin protein was detected and the minimum inhibitory concentration (MIC) values were determined using broth microdilution techniques. Time-killing assays were performed on the Gram-negative bacteria,Acinetobacter baumannii, at the logarithmic or stabilizing stages of growth, and its morphological changes when treated with Cec4 were assessed by scanning electron microscopy (SEM) and detection of leakage of 260 nm absorbing material.ResultsEleven cecropin family genes, namelyCec01,Cec02andCec1-9, show homology to the Cec form in a multigene family on the Scaffold18749 ofM. domestica. In comparing the encoded cecropin protein sequences, most of them have the basic characteristics of the cecropin family, containing 19 conservative amino acid residues. To our knowledge, this is the first experimental demonstration that most genes in the Cec family are functional. Cec02, Cec1, Cec2, Cec5 and Cec7 have similar antibacterial spectra and antibacterial effects against Gram-negative bacteria, while Cec4 displays a more broad-spectrum of antimicrobial activity and has a very strong effect onA. baumannii. Cec4 eliminatedA. baumanniiin a rapid and concentration-dependent manner, with antibacterial effects within 24 h at 1× MIC and 2× MIC. Furthermore, SEM analysis and the leakage of 260 nm absorbing material detection indicated that Cec4 sterilized the bacteria through the disruption of cell membrane integrity.ConclusionsAlthough there are more than ten cecropin genes related toM. domestica, some of them have no preferred antibacterial activity other than Cec4 againstA. baumannii.

In this paper, a robust adaptive control method based on back-stepping approach is presented to deal with adaptive control of a class of nth-order nonlinear systems with unknown backlash-like hysteresis and unknown external disturbance. The backlash-like hysteresis is modelled by a differential equation. The control algorithm can ensure the global stability of the nonlinear closed loop system and the actual output can track the reference output well. Two examples illustrate and verify the performance of the new proposed control scheme. This method may be used in the mechanical actuators, piezo-electric materials, and tendon sheath mechanism system.

The transposon vector containing enhanced green fluorescent protein (EGFP) was injected into early housefly (Musca domestica L.) eggs by microinjection method to realize stable gene expression in vivo for verification, and to study housefly gene function. A borosilicate glass micro injection needle suitable for microinjection of housefly eggs was made, the softening treatment conditions of housefly egg shells were explored, and a microinjection technology platform suitable for housefly was constructed with a high-precision microsyringe Nanoject Ⅲ as the main body. The recombinant plasmid PiggyBac-[3×P3]-EGFP containing the eye-specific 3×P3 promoter and EGFP and the stable genetic expression helper plasmid pHA3pig helper were microinjected into the treated housefly eggs. After emergence, the eye luminescence was observed, and the expression and transcription level of EGFP were detected. The results showed that the normal hatching rate of housefly eggs was 55% when rinsed in bleaching water for 35 s. The hardness of the egg shell treated for 35 s was suitable for injection and the injection needle was not easy to break. About 3% of the emerged housefly eyes had green fluorescence. Through further molecular detection, EGFP specific fragments with a size of 750 bp were amplified from DNA and RNA of housefly. Through the technical platform, the stable expression of reporter genes in housefly can be conveniently and effectively realized, and a bioreactor with housefly as the main body can be established, which provides certain reference value for subsequent research on housefly gene function.旨在利用显微注射法对早期家蝇 (Musca domestica L.) 卵注射含有增强型绿色荧光蛋白 (Enhanced green fluorescent protein，EGFP) 基因的转座子载体，实现活体基因稳定表达并对其进行验证，为开展家蝇基因功能的研究奠定基础。文中自制适用于显微注射家蝇卵的硼硅酸盐玻璃微量注射针，摸索出家蝇卵壳的软化处理条件，以Nanoject Ⅲ高精度微量注射器为主体构建适用于家蝇的显微注射技术平台；将含有眼部特异表达的3×P3启动子、EGFP的重组质粒PiggyBac-[3×P3]-EGFP与稳定遗传表达辅助质粒pHA3pig helper显微注射到处理过的家蝇卵中，待羽化观察眼部发光情况，检测EGFP的表达及转录水平。结果表明，将家蝇卵在漂白水中漂洗35 s时卵的正常孵化率为55%，处理35 s的卵壳其硬度适宜注射且注射针头不易破碎；羽化后的家蝇眼部带有绿色荧光的占比约为3%，通过分子检测，家蝇的DNA和RNA中均扩增出EGFP特异片段，大小为750 bp。通过该技术平台，能够便捷、有效地实现报告基因在家蝇中的稳定表达，建立以家蝇为主体的生物反应器，为后续家蝇基因功能的研究提供一定参考价值。.

In most insects, polyunsaturated fatty acids (PUFAs) are mainly polyunsaturated fatty acids with a carbon-chain length less than 18 carbon atoms, hardly any long-chain polyunsaturated fatty acids such as C20 and C22 that are more valuable and bioactive. This study, by using Drosophila melanogaster (Fruit fly) as a model organism, optimized the Δ6-fatty acid elongase enzyme Elovl5 gene from mice and transferred it to fruit flies for expression. Vectors containing Elovl5 gene were successfully injected into drosophila embryo through the microscopic injection. There were enhanced green fluorescent proteins expressed in the whole developmental stage of Drosophila be means of fluorescence microscope. At the same time, expression of Elovl5 gene significantly contributed to the transformation of fruit flies C18-polyunsaturated fatty acids in the body towards the biosynthesis of longer-chain polyunsaturated fatty acids. The transgenic fruit fly model rich in long-chain polyunsaturated fatty acids such as C20 and C22 were obtained, providing a basis for further research on biosynthesis of polyunsaturated fatty acids in fruit flies.大多数昆虫体内的多不饱和脂肪酸 (Polyunsaturated fatty acids，PUFAs) 主要是碳链长为18 个碳原子的多不饱和脂肪酸 (C18-PUFAs)，几乎不含价值更高、生物活性更强的C20、C22 等长链的多不饱和脂肪酸。文中利用黑腹果蝇Drosophila melanogaster (Fruit fly) 作为生物模型，将来源于小鼠的Δ6-脂肪酸延长酶Elovl5 基因优化后转移到果蝇中使其表达。结果表明通过显微注射法成功将含有Elovl5 基因的载体导入果蝇胚胎中，在荧光显微镜下检测到在果蝇整个发育阶段均有增强型绿色荧光蛋白 (Enhanced green fluorescent protein，EGFP) 表达，同时Elovl5 基因的表达显著地促使果蝇体内C18 多不饱和脂肪酸向着更长链多不饱和脂肪酸的生物合成方向转化。使用转基因技术得到体内富含C20、C22 等长链多不饱和脂肪酸的转基因果蝇模型，将为进一步开展果蝇多不饱和脂肪酸生物合成的机制提供研究基础。.

Additional file 1: Table S1. Primer sequences used for cloning in this study.

This paper introduced the basic situation and layout of Chemical Industry Park (concentration) in Jiangsu Province. There are some problems in the park: Due to the relevant planning of chemical industry park is proposed in recent years, part of the park planning is missing, and the planning at all levels is not coordinated; Due to the early site selection and construction of some parks, the lack of overall planning, the problems of planning red line crossing enterprises and residential areas in the park, and the imperfect infrastructure construction of the park; due to the authority of examination and approval for the establishment of institutions and personnel in the park, the responsibilities of some institutions in the park are not clear, and the number of professional supervisors is insufficient; In view of the problems existing in the park, this paper puts forward relevant countermeasures and suggestions from the aspects of the integrity of the park planning, the rationality of the location and layout, the compliance of the organization and personnel, and the importance of the park infrastructure.

In this work, anatase-TiO2 is investigated as a catalyst support in Pd/TiO2–C composite to improve the electrocatalytic properties of Pd for formic acid oxidation reaction (FAOR). Pd/TiO2 has been synthesized by an impregnation-reduction method and then mixed with Vulcan XC-72R carbon black to obtain Pd/TiO2–C composite. Transmission electron microscopy (TEM) images show Pd nanoparticles (ca.3.5 nm in average diameter) in the Pd/TiO2–C (1:1) composite catalyst were dispersed on the surface of TiO2 with a narrow particle size distribution. Electrochemical tests demonstrate Pd/TiO2–C (1:1) composite has significantly increased catalytic activity and stability compared with Pd/C for FAOR. The proposed reasons for these observations are the excellent acid corrosion and oxidation resistance of TiO2 and the synergistic effect of Pd and TiO2 nanoparticles. The effect of mass ratios of TiO2 to C on the catalytic performance is also discussed. The best catalytic activity and stability for FAOR is found when the mass ratio of TiO2 to C is 1:1. It can be interpreted as the synergistic effects and conductivity reach balance at this point.

Mobius cube and deBruijn digraph have been proved to be two of the most popular interconnection architectures, due to their desirable properties. Some of the attractive properties of one, however, are not found in the other. The Mobius-deBruijn architecture, proposed in this paper, is the product of Mobius cube and deBruijn digraph, which is a combination of the two architectures. It employs the Mobius cube as a unit cluster and connects many such clusters by means of given number of parallel deBruijn digraphs. Consequently, the Mobius-deBruijn provides some of the desirable properties of both the architectures, such as the flexibility in terms of embedding of parallel algorithms, the high level of fault-tolerant, and the efficient inter-cluster communication. The proposed architecture also possesses the logarithmic diameter, the optimal connectivity, and the simple routing mechanism amenable to network faults. The methodology to construct the Mobius-deBruijn can apply to the product of deBruijn digraph and other hypercube-like networks, and also applies to the product of Kautz digraph and hypercube-like networks.

DHA (22:6n-3) is a Ω-3 polyunsaturated fatty acid with 22 carbon atoms and 6 double bonds, which has important biological functions in human body. Human and other mammals synthesize only limited amounts of DHA, more requirements must be satisfied from food resources. However, the natural resources of DHA (Mainly deep-sea fish and other marine products) are prone to depletion. New resources development is still insufficient to satisfy the growing market demand. Previous studies have revealed that the mammals can increase the synthesis of DHA and other long-chain polyunsaturated fatty acids after transgenic procedures. In this study, mammalian cells were transfected with Δ6, Δ5 desaturase, Δ6, Δ5 elongase, Δ15 desaturase (Isolated from nematode Caenorhabditis elegans) and Δ4 desaturase (Isolated from Euglena gracilis), simultaneously. Results show that the expression or overexpression of these 6 enzymes is capable of conversion of the o-6 linoleic acid (LA, 18:2n-6) in DHA (22:6n-3). DHA content has increased from 16.74% in the control group to 25.3% in the experimental group. The strategy and related technology in our research provided important data for future production the valuable DHA (22:6n-3) by using genetically modified animals.

Three long-chain polyunsaturated fatty acids, docosahexaenoic acid (DHA, 22:6n-3), eicosapentaenoic acid (EPA, 20:5n-3) and arachidonic acid (ARA, 20:4n-6), are the most biologically active polyunsaturated fatty acids in the body. They are important in developing and maintaining the brain function, and in preventing and treating many diseases such as cardiovascular disease, inflammation and cancer. Although mammals can biosynthesize these long-chain polyunsaturated fatty acids, the efficiency is very low and dietary intake is needed to meet the requirement. In this study, a multiple-genes expression vector carrying mammalian A6/A5 fatty acid desaturases and multiple-genes expression vector carrying mammalian Δ6/Δ5 fatty acid desaturases and Δ6/Δ5 fatty acid elongases coding genes was used to transfect HEK293T cells, then the overexpression of the target genes was detected. GC-MS analysis shows that the biosynthesis efficiency and level of DHA, EPA and ARA were significantly increased in cells transfected with the multiple-genes expression vector. Particularly, DHA level in these cells was 2.5 times higher than in the control cells. This study indicates mammal possess a certain mechanism for suppression of high level of biosynthesis of long chain polyunsaturated fatty acids, and the overexpression of Δ6/Δ5 fatty acid desaturases and Δ6/Δ5 fatty acid elongases broke this suppression mechanism so that the level of DHA, EPA and ARA was significantly increased. This study also provides a basis for potential applications of this gene construct in transgenic animal to produce high level of these long-chain polyunsaturated fatty acid.

Trust and reputation have been recognized as a key issue in the area of multi-agent systems. And till now, a number of researchers have, in different perspectives, reviewed/surveyed the notions, techniques or models of trust and reputation. However, the notion of trust and reputation still remains somewhat vague, and the techniques and model is yet understood in a disunited way. This paper categorizes the notions, techniques, and models of trust and reputation in terms of the trust management process which can be characterized through three questions: a) why does an agent trust another; b) how do agents judge or evaluate the trustworthiness of others; c) what does an agent do after obtaining the trustworthiness of others. These questions present a unified view of trust and reputation. The two aspects implied in the first question suggest two different understanding of the notion of trust. The second question refers to the techniques of getting and dealing with two different types of trust evidence. And it comes to the third question when trust models take agents' post-evaluation actions and the effect of these actions on their partners/opponents into account to make themselves incentive-compatible.

Arachidonic (ARA), eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids are the most biologically active polyunsaturated fatty acids, but their biosyntheses in mammals are very limited. The biosynthesis of DHA is the most difficult, because this undergoes the Sprecher pathway--a further elongation step from docosapentaenoic acid (DPA), a Δ6-desaturase acting on a C24 fatty acid substrate followed by a peroxisomal chain shortening step. This paper reports the successful heterologous expression of two non-mammalian genes (with modification of codon usage), coding for Euglena gracilis Δ4-desaturase and Siganus canaliculatus Δ4-desaturase respectively, in mammalian cells (HEK293 cell line). Both of the Δ4-desaturases can efficiently function, directly converting DPA into DHA. Moreover, the cooperation of the E. gracilis Δ4-desaturase with C. elegans Δ15-desaturase (able to convert a number of n-6 PUFAs to their corresponding n-3 PUFAs) in transgenic HEK293 cells made a more desirable fatty acid composition--a drastically reduced n-6/n-3 PUFAs ratio and a high level of DHA as well as EPA and ARA. Our findings provide a basis for potential applications of the gene constructs for expression of Δ15/Δ4-desaturases in transgenic livestock to produce such a fatty acid profile in the related products, which certainly will bring benefit to human health.