Investigating the Effects of Particle Size on the Growth of Silkworm and Fiber Properties with Feeding TiO2 NPs

The production method of functional silk by feeding the various nanoparticles is simple, it has attracted the attention of many researchers. However, many researchers have studied the concentrate of nanoparticles (NPs), there are few studies on the particle size. This study is aimed to confirm the effects in silkworm growth, cocoon quality, and mechanical properties of silk with feeding TiO2 NPs of the various particle size. TiO2 10nm, 50nm, 100nm powers individually are fed to silkworm, investigated the mortality and proliferation rate, cocoon mass and cocoon shell mass, mechanical characteristic of silk fiber. The experiments demonstrated that the larger the particle size of TiO2 NPs, the greater the adverse impact on the growth and livability of silkworms. The stress of 523.35±42 MPa and strain of 19.73±1.8% of the TiO2-10nm added silk were increased 35.9% and 19.5% on average, respectively. By the analysis of the Fourier transform infrared (FTIR) spectra, it was confirmed that this resulted in a more random coil/?-helix structure. The nanoparticles are acted as knots, forming the cross-linked network, resulting in lower crystallinity and higher strain, but the larger the particle, the fewer the number of knots, at the same time, it has a great impact on protein synthesis, and then the strength may be decreased. The effect in the silkworm body of TiO2 NPs particle size has to be deeply studied, but this study has important significance to study in the production of the functional silk by feed additives.

Properties Change of Korean Traditional Animal Glue Depending on The Parts of Cattle Hide and Extraction Conditions

We investigated the properties of Korean traditional animal glue which are associated with the use of different parts of cattle hide and extraction conditions. Both average molecular weight(Mw, Mz) and polydispersity (PDI) of the animal glue increased with extraction time, whereas only PDI decreased after 48h. There were no differences in the average molecular weight and PDI for the different cattle hide parts used, although a individual difference was observed with regard to total molecular weight. Differences in extracts over time were compared by investigating the amide regions representing the gelatien component of the animal glue. The triple helix structure of the belly skin deteriorated in a manner proportional to the extraction time, and differences were observed for each cattle hide part. The yellowness increased with the extraction time; however, the viscosity was not proportional to the average change in molecular weight. This study has some limitations because of difficulties in the quality control of cases where small amounts of glue were extracted as small differences might impact the overall results considerably. Further research exploring various extraction conditions is required to ensure the prodiction of traditional animal glue with optimum qualities.

Anionic surfactant sulfate dodecyl sodium (SDS)-induced thermodynamics and conformational changes of collagen by ultrasensitive microcalorimetry

In this communication, sulfate dodecyl sodium (SDS)-induced thermodynamics and conformational changes of collagen were studied. We used ultrasensitive differential scanning calorimetry (US-DSC) to directly monitor the thermal transition of collagen in the presence of SDS. The results show that SDS affects the conformation and thermal stability of collagen very differently depending on its concentrations. At CSDS ≤ 0.05 mM, the enhanced thermal stability of collagen indicates the stabilizing effect by SDS. However, a further increase of SDS leads to the denaturation of collagen, verifying the well-known ability of SDS to unfold proteins. This striking difference in thermodynamics and conformational changes of collagen caused by SDS concentrations can be explained in terms of their interactions. With increasing SDS, the binding of SDS to collagen can be dominated by electrostatic interaction shifting to hydrophobic interaction, and the latter plays a key role in loosening and unfolding the triple-helix structure of collagen. The important finding in the present study is the stabilizing effect of SDS on collagen molecules at extreme low concentration. Graphical abstract

Recovery of Gelatin from Bovine Skin with the Aid of Pepsin and Its Effects on the Characteristics of the Extracted Gelatin

Pepsin enzyme was used to pretreat the bovine skin at the rate of 5, 15, and 25 units of enzyme/g of skin to recover gelatin, and the recovered gelatins were referred to as Pe5, Pe15, and Pe25, respectively. The gelatin yield increased significantly (p < 0.05) from 18.17% for Pe5 to 24.67% for Pe25 as the level of pepsin increased, but the corresponding gel strength and viscosity decreased significantly (p < 0.05) from 215.49 to 56.06 g and 9.17 to 8.17 mPa.s for Pe5 and Pe25, respectively. β- and α1- and α2-chains were degraded entirely in all the gelatins samples as observed in protein pattern elaborated by gel electrophoresis. 1H nuclear magnetic resonance (1H NMR) analysis indicated the coiled structure of gelatin protein chains. The lowest amide III amplitude of Pe25 as found by Fourier transform infrared (FTIR) spectroscopy indicated that α-helix structure of protein chains were lost to more irregular coiled structure. Thus, it could be summarized that pepsin might be used at the lower level (5 units/g of wet skin) to extract gelatin from bovine skin with good functional properties and at higher level (15/25 units/g of wet skin) to obtain gelatin of industrial grade with high yield.

The Secret of Ishango – On the helix structure of prime numbers

The Ishango bones were found in the 1950s by Belgian archaeologist Jean de Heinzelin near a Palaeolithic residence in Ishango, Africa. Inscriptions, which can be interpreted as numbers, make these bones the oldest mathematical find in human history. Interestingly, on one of the two Ishango bones, we also find the six consecutive prime numbers 5, 7, 11, 13, 17 and 19. Did Stone Age people already know the secret of the prime numbers? This question is explored in my mathematical essay “The Secret of Ishango”, an adventurous journey around the world from Basel in Switzerland to Erode in India. The presumed connection between the numbers on the Ishango bones and the structure of the prime numbers is illustrated by a sketch at the end of the text. Are the prime numbers organized as a double helix like DNA? As the physicist and mathematician Freeman John Dyson said so beautifully: “For any speculation which does not at first glance look crazy, there is no hope.”