Advanced Materials Research Vol. 796

Abstract: Trimolter silk fiber has special economic value and bright prospect in terms of developing the distinctive silk textile of high quality. In this research, the trimolters were induced by AJH (Jinlu inducer) using two races of silkworms (Qiufeng×Baiyu and Liangguang NO.2) as materials, and their cocoon and silk quality differences were investigated with single cocoon reeling test The results showed that the cocoon filament denier were different because of silkworm races and treatment periods The cocoon filament deniers from the controls, 3^rd instar and 4^th instar treatment groups of Liangguang NO.2 were 2.64 D, 1.45D and 0.78 D, while the cocoon filament deniers of Qiufeng×Baiyu were 2.47 D, 1.75 D and 1.01 D, respectively. Compared with the controls, the breakage strength of silk fiber from 3^rd instar treatment groups of Qiufeng×Baiyu and Liangguang NO.2 enhanced 109.6 % and 145.2 %, on the contrary, that of 4^th instar treatment groups declined to 70.3 % and 43.6 %. Additionally, sericin tended to decrease after the treatment of AJH. These results showed that fine filament silk with high quality could be produced in the early stage of 3^rd instar induced by AJH, which was superior to that of tetramolters, and the super fine filament silk can be produced in the stage of 4^th instar induced by AJH.

Abstract: Fruit mulberry cultivation has become a new field of modern sericulture, and quite a number of studies were focused on the growth and development of mulberry flowers and fruits. In order to explore the molecular mechanism of development and regulation of mulberry pistillate flower, the total protein were extracted from the flowering style (with the stigma) and ovary with fruit mulberry variety "Da 10" as materials, separated by two-dimensional electrophoresis and identified by mass spectrometry. The results showed that there were significant differential expressions in different tissues, and 20 proteins with specific expression were detected in the style of pistillate flower. By mass spectrometry analysis, database retrieval and bioinformatics software analysis, these protein components were given functional annotation, mainly related to the biosynthetic metabolism of protein and flavonoid, stress response and redox reaction. Additionally, glucan endo-1,3-beta-glucosidase involved in cell wall metabolism was detected to be up-regulated expression and lipoxygenase participating in membrane lipid oxidation reaction was detected to be down-regulated expression in the style compared with that in the ovary. It illustrated that the differential expression of these proteins in style were closely related to pollen germination, pollen tube growth or intrusion of other xenobiotics.

Abstract: The silkworm fat body is the organ of many intermediary metabolic processes and sustenance of growth throughout the life, and its proteins are responsible for storing nutrients, providing energy and regulating hormones. To date, detailed differential expressions of fat body proteins have not been clearly analyzed. In this research, fat body proteins were extracted from the larvae of the 5^th day of the 5^th instar, un-pupated larvae of spinning end and pupae of pupating day of the multivoltine silkworm variety Da Zao, and the differential expressed proteins were characterized by two-dimensional gel electrophoresis, followed by mass spectrometry identification and informatics method. 14 stage-specific expression proteins were detected and confirmed. Among them, 7 proteins were accurately identified, such as actin, calponin-like protein, beta-tubulin, hypothetical protein, antichymotrypsin precursor and 30K protein precursor etc. The biological roles of these important proteins during the larval-pupal developmental stages were discussed.

Abstract: Serpin (Serine Protease Inhibitor) widely distributes in animals, plants, protozoan, prokaryotes and viruses. Serpin-6 belongs to the superfamily of serine protease inhibitor. In this study, we constructed a prokaryotic vector - pET28a-serpin-6, and used IPTG (isopropyl thiogalactoside) to induce serpin-6 protein expression, then applied the Ni-affinity chromatography to purify the collected recombinant protein. The assay of SDS-PAGE and Anti-his Polyclonal antibody Test showed that the recombinant serpin-6 protein have a molecular weight of 45 kDa. The highly purified sample of the recombinant protein was obtained. The protein has been used as antigen to immunize KunMing mice using the 4 times immunization method. We successfully attained the polyclonal antibody of serpin-6.The titer of the antibody is as high as 1:20000, with a good specificity. The polyclonal antibody can provide a practical tool to further study the distribution of protein expression and functions of serpin-6 in different states and breeds of Bombyx mori.

Abstract: Objective: To explore the effects of the biodegradability of biomaterial scaffolds on skin tissue regeneration and its neovascularization by the animal experiments. Methods: A piece of porous silk fibroin film (SF) of easy biodegradation and a piece of porous polyvinyl alcohol film (PVA) of hard biodegradation were implanted into a same skin wound of adult rat, and the differences in the regenerative blood vessel and tissue at 5, 10, 16, 41 days after surgery were observed by histological methods. Results: (1) at 10 days after surgery, the SF started to degrade, the closed areas without cell infiltration were opened up and the entire material was filled with the regenerative tissue, and there were still the closed areas in the PVA, (2) the new vascular network remodeling in the SF and PVA appeared at 10 days and 41 days after surgery, respectively, and (3) at 16 days after surgery, most of the SF material had degraded and substantially been replaced with the regenerative tissue, and the visible degradation of the PVA appeared at 41 days after surgery. Conclusion: The good biodegradability of the SF was helpful both to all vascularization of the material and to the regenerative blood vessels remodeling, and the regenerative tissue was closer to the normal dermal tissue than in the PVA.

Abstract: A block combination genes (gx16-f) was designed and cloned for encoding GX16-F, which was derived from the crystalline domain (X: A, S, V or Y, GA: GAGAGA, GS: GAGAGS, GV: GAGAGV and GY: GAGAGY) and the amorphous domain (F=SGFGPVANGGSGEASSESDFGSSGFGPVANASSGEASSESDFAG) of Bombyx mori silk fibroin heavy chain. The combination genes were then cloned into a GST-tagged prokaryotic expression vector for expression of protein. Agarose gel electrophoresis analysis and DNA sequencing demonstrated that the combination gene encoding GX16-F was accurately cloned, and inserted into the expression vector successfully. The study would provide a technology to produce different structural polypeptides for studying the structurefunction relationships of silk fibroin.

Abstract: Alginate fibers were prepared by extruding a concentrated sodium alginate solution into calcium chloride coagulation bath. The rheological behavior of different concentrations of sodium alginate solutions were investigated to evaluate the spinnability. The effect of dope concentration on the morphologies and mechanical properties of resulting alginate fibers were examined. The results showed that sodium alginate solutions were pseudoplastic fluid and had good spinnability with concentration ranging in 1.5%-3.5%. Moreover, the morphology of obtained fibers became smoother with increasing sodium alginate concentrations. When the sodium alginate concentration was 3.5%, the tensile strength and elongation at break of alginate fibers reach to 13.6±1.2 cN/tex and 8±0.5%, respectively.

Abstract: Due to the advantages of both the chitosan and the nanomaterial, chitosan nanoparticle has a broad application in a lot of fields, such as medicine carrier, food process, cosmetics and agriculture protect. And there also appears a lot of research about chitosan nanoparticle in textile finishing in recent years. In former research, steady state chitosan nanoparticles were prepared by ionotropic gelation method in dispersion system. In this paper, in order to confirm the preparation of low molecular weight chitosan nanoparticle, it was also characterized by Fourier Transform Infrared (FT-IR) Spectrometry, X-ray diffraction (XRD) and Transmission Electron Microscope (TEM). Focusing on the application value, chitosan nanoparticles dispersion solution were used as one kind of textile finishing agent to modify B.mori silk fabrics in order to realize the functionalization of silk fabrics. The wrinkle resistance and bacteria repellency of silk fabrics were tested in the paper. The results showed that chitosan nanoparticles were successfully prepared and confirmed accrording to the XRD, FT-IR and TEM tests. In addition, compared with the ordinary B. mori silk fabric and the B. mori silk fabric treated with chitosan accordingly, the B. mori silk fabrics treated with chitosan nanoparticle dispersion system had better wrinkle resistance and bacteria repellency.

Abstract: In this thesis, stable nanoMgO particles were prepared by precipitation process, using analytical pure MgCl₂·6H₂O and NH₃·H₂O as the raw materials, which MgCl₂ as the source of magnesium and NH₃·H₂O as the precipitating agent. The dispersant of PAAS and SHMP in appropriate dosage was also needed. The nanoMgO particles were characterized by using techniques such as Infrared Spectroscopy, Absorbance Determination, Scanning Electron Microscopy and tested by Laser Particle Size Analyzer. The nanoMgO finishing agent is prepared in the condition of ultrasonic oscillation by optimized processes which involve the choosing of appropriate dispersant. Finally, the good UV protection and antibacterial silk fabrics was obtained through functional finishing by impregnating process on silk fabrics under treated by peregal-O. This work lays a foundation for the research and application of nanoscale finishing agent preparation with the low cost. The results showed that the stability of prepared nanoMgO particles is considerable, the durability of the finished fabrics is satisfactoried.

Abstract: Abstract: Boehmite (AlOOH) has been prepared from AlCl3·6H2O and ammonia by a hydrothermal method. The products obtained under different conditions were characterized by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM). The results show that the as-prepared AlOOH is stable, transparent, and crystalline, and it is rodlike with an average diameter of about 5 nm and a length of about 100 nm. The reaction temperature and time have important influences on the diameter and uniformity of the products. Besides, it was found that the anti-ultraviolet effect of silk-cotton fabrics was improved significantly after finishing by nano AlOOH solution.