scholarly journals Recombinant Silk Proteins with Additional Polyalanine Have Excellent Mechanical Properties

2021 ◽  
Vol 22 (4) ◽  
pp. 1513
Author(s):  
Shuo Zhao ◽  
Xiaogang Ye ◽  
Meiyu Wu ◽  
Jinghua Ruan ◽  
Xiaoxiao Wang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Large Scale ◽  
Scale Production ◽  
Large Scale Production ◽  
Foreign Proteins ◽  
Transgenic Silkworms ◽  
Type 3 ◽  
Silkworm Silk ◽  
Β Sheet ◽  
Fibroin Light Chain

This paper explores the structures of exogenous protein molecules that can effectively improve the mechanical properties of silkworm silk. Several transgenic vectors fused with the silkworm fibroin light chain and type 3 repeats in different multiples of the ampullate dragline silk protein 1 (MaSp1) from black widow spider with different lengths of the polyalanine motifs were constructed for this study. Transgenic silkworms were successfully obtained by piggyBac-mediated microinjection. Molecular detection showed that foreign proteins were successfully secreted and contained within the cocoon shells. According to the prediction of PONDR® VSL2 and PONDR® VL-XT, the type 3 repeats and the polyalanine motif of the MaSp1 protein were amorphous. The results of FTIR analysis showed that the content of β-sheets in the silk of transgenic silkworms engineered with transgenic vectors with additional polyalanine was significantly higher than that of wild-type silkworm silk. Additionally, silk with a higher β-sheet content had better fracture strength and Young’s modulus. The mechanical properties of silk with longer chains of exogenous proteins were improved. In general, our results provide theoretical guidance and technical support for the large-scale production of excellent bionic silk.

scholarly journals Effect of Different Additives in Diets on Secondary Structure, Thermal and Mechanical Properties of Silkworm Silk

Materials ◽  
2018 ◽  
Vol 12 (1) ◽  
pp. 14 ◽  
Author(s):  
Lan Cheng ◽  
Huiming Huang ◽  
Jingyou Zeng ◽  
Zulan Liu ◽  
Xiaoling Tong ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Amino Acid ◽  
Large Scale ◽  
Fiber Composites ◽  
Metallic Ions ◽  
Silk Fibers ◽  
Random Coils ◽  
Silkworm Silk ◽  
Β Sheet

In this study, eight types of materials including nanoparticles (Cu and CaCO3), metallic ions (Ca2+ and Cu2+), and amino acid substances (serine, tyrosine, sericin amino acid, and fibroin amino acid) were used as additives in silkworm diets to obtain in-situ modified silk fiber composites. The results indicate that tyrosine and fibroin amino acids significantly increase potassium content in silk fibers and induce the transformation of α-helices and random coils to β-sheet structures, resulting in higher crystallinities and better mechanical properties. However, the other additives-modified silk fibers show a decrease in β-sheet contents and a slight increase or even decrease in tensile strengths. This finding provides a green and effective approach to produce mechanically enhanced silk fibers with high crystallinity on a large scale. Moreover, the modification mechanisms of these additives were discussed in this study, which could offer new insights into the design and regulation of modified fibers or composites with desirable properties and functions.

scholarly journals Multivalent and Multipathogen Viral Vector Vaccines

2016 ◽  
Vol 24 (1) ◽  
Author(s):  
Katharina B. Lauer ◽  
Ray Borrow ◽  
Thomas J. Blanchard
Keyword(s):  
Immune Response ◽  
Measles Virus ◽  
Viral Vectors ◽  
Large Scale ◽  
Viral Vector ◽  
Natural Infection ◽  
Scale Production ◽  
Veterinary Vaccine ◽  
Large Scale Production ◽  
Foreign Proteins

ABSTRACT The presentation and delivery of antigens are crucial for inducing immunity and, desirably, lifelong protection. Recombinant viral vectors—proven safe and successful in veterinary vaccine applications—are ideal shuttles to deliver foreign proteins to induce an immune response with protective antibody levels by mimicking natural infection. Some examples of viral vectors are adenoviruses, measles virus, or poxviruses. The required attributes to qualify as a vaccine vector are as follows: stable insertion of coding sequences into the genome, induction of a protective immune response, a proven safety record, and the potential for large-scale production. The need to develop new vaccines for infectious diseases, increase vaccine accessibility, reduce health costs, and simplify overloaded immunization schedules has driven the idea to combine antigens from the same or various pathogens. To protect effectively, some vaccines require multiple antigens of one pathogen or different pathogen serotypes/serogroups in combination (multivalent or polyvalent vaccines). Future multivalent vaccine candidates are likely to be required for complex diseases like malaria and HIV. Other novel strategies propose an antigen combination of different pathogens to protect against several diseases at once (multidisease or multipathogen vaccines).

scholarly journals Electromagnetic wave absorption polyimide fabric prepared by coating with core–shell NiFe2O4@PANI nanoparticles

RSC Advances ◽  
2017 ◽  
Vol 7 (68) ◽  
pp. 42891-42899 ◽  
Author(s):  
Yu Wang ◽  
Wei Wang ◽  
Meifang Zhu ◽  
Dan Yu
Keyword(s):  
Mechanical Properties ◽  
Electromagnetic Wave ◽  
Large Scale ◽  
Core Shell ◽  
Scale Production ◽  
Electromagnetic Wave Absorption ◽  
Wave Absorption ◽  
Microwave Attenuation ◽  
Large Scale Production

The NiFe2O4@PANI/PI fabric exhibited excellent microwave attenuation performance, favorable mechanical properties and was appropriate for large-scale production.

Facile, continuous and large-scale production of core–shell HMX@TATB composites with superior mechanical properties by a spray-drying process

RSC Advances ◽  
2015 ◽  
Vol 5 (27) ◽  
pp. 21042-21049 ◽  
Author(s):  
Zhigang Ma ◽  
Bing Gao ◽  
Peng Wu ◽  
Jinchun Shi ◽  
Zhiqiang Qiao ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Spray Drying ◽  
Shell Structure ◽  
Large Scale ◽  
Core Shell ◽  
Scale Production ◽  
Drying Process ◽  
Large Scale Production ◽  
Superior Mechanical Properties ◽  
Shell Content

Core–shell HMX@TATB composites with low shell content and compact shell structure were fabricated via a facile and effective spray-drying technique.

Sialon Ceramics Sintered with Yttria and Rare Earth Oxides

1992 ◽  
Vol 287 ◽  
Author(s):  
Thommy EkstrÖm
Keyword(s):  
Mechanical Properties ◽  
Rare Earth ◽  
High Temperatures ◽  
Large Scale ◽  
Low Cost ◽  
Rare Earth Oxides ◽  
Boundary Phase ◽  
Scale Production ◽  
Large Scale Production ◽  
Very High

ABSTRACTDense single-phase α-, β- and O′-sialon cermics or mixed sialon ceramics without a glassy grain-boundary phase can be prepared at high temperatures and pressures, and these materials are well suited for high-temperature use, but they are usually brittle. Additional quantities of oxides of group IIIB metals in the periodic table are often added as sintering aids to achieve pressureless sintering and thereby to allow more complicated shapes to be manufactured directly and at lower costs. The most common additive is yttria, but the rare earth oxides are also of interest. All these oxides will promote the growth of elongated β crystals in the microstructure, and the fracture toughness will be improved considerably. Low-cost oxides like Nd2O3, La2O3 or CeO2 may replace Y2O3 without significantly impairing the mechanical properties at room temperature. The expensive rare-earth oxides like Sm2O3, Dy2O3 or Yb2O3 have been found to be as good additives as yttria, or even better, but improvements in mechanical properties are generally small and do not justify the use of these additives in large-scale production. The residual intergranular glassy phase usually found in the microstructure of metal-oxide-doped sialons will deteriorate the properties at very high temperatures, and this type of material is best suited for use at operation temperatures below 900-1000°C.

scholarly journals Induction and characterization of oil palm (Elaeis guineensis Jacq.) pro-embryogenic masses

2013 ◽  
Vol 85 (4) ◽  
pp. 1545-1556 ◽  
Author(s):  
MARLUCIA S. PADUA ◽  
LUCIANO V. PAIVA ◽  
CLAUDIA R.G. LABORY ◽  
EDUARDO ALVES ◽  
VANESSA C. STEIN
Keyword(s):  
Oil Palm ◽  
Large Scale ◽  
Elaeis Guineensis ◽  
Leaf Explants ◽  
Scale Production ◽  
Large Scale Production ◽  
Type 3

ABSTRACT Oil palm is one of the most economically valuable oil seed plants, but the expansion of plantations has been limited by availability of seedlings, as the conventional propagation is through seeds, which have low germination rates. One possible solution for the large-scale production is the use of somatic embryogenesis. The aim of this study was evaluate the effects auxins 2,4-D and picloram on the induction of pro-embryogenic masses in E.guineenesis hybrid leaf explants and characterize, regarding embryogenic characteristics, with cytochemical and ultrastructural analisys. Specifically, in vitro plantlets leaves fragments were inoculated in Y3 culture medium supplemented by 2.4-D or picloram at different concentrations (0.0, 1.0, 3.0, 6.0 and 9.0 mg l–1). After 90 days the presence/ absence of cell masses were evaluated. Both growth regulators efficiently induced cellular masses regardless of the concentrations applied. As the cell masses were not homogeneously formed, they were classified according to color and shape into four types: TYPE 1 - elongated and translucent, TYPE 2 – uneven and translucent, TYPE 3 - globular and beige TYPE 4 – globular and white. Based on the anatomical and ultrastructural features, TYPE 2, 3 and 4 cell masses were considered to have the highest embryogenic potential and therefore may be most suited to large-scale vegetative propagation of oil palm.

I. S. A. Baud. Forms of Production and Women's Labour: Gender Aspects of Industrialisation in India and Mexico. New Delhi: Sage Publications. 1992. 321 pp.Hardbound. Price: Indian Rs 295.00.

1993 ◽  
Vol 32 (1) ◽  
pp. 129-131
Author(s):  
Naureen Talha
Keyword(s):  
Large Scale ◽  
Indian Society ◽  
New Delhi ◽  
Scale Production ◽  
Female Labour ◽  
Self Employment ◽  
Commodity Production ◽  
Large Scale Production ◽  
Mexican Society ◽  
Small Production

The literature on female labour in Third World countries has become quite extensive. India, being comparatively more advanced industrially, and in view of its size and population, presents a pictures of multiplicity of problems which face the female labour market. However, the author has also included Mexico in this analytical study. It is interesting to see the characteristics of developing industrialisation in two different societies: the Indian society, which is conservative, and the Mexican society, which is progressive. In the first chapter of the book, the author explains that he is not concerned with the process of industrialisation and female labour employed at different levels of work, but that he is interested in forms of production and women's employment in large-scale production, petty commodity production, marginal small production, and self-employment in the informal sector. It is only by analysis of these forms that the picture of females having a lower status is understood in its social and political setting.

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