Derivatization of the low-priced commercial retinol for the anti-aging cosmetics

A retinol is a well-known source material for the anti-aging cosmetics due to its superior effects on the anti-wrinkle and anti-skin aging, and lots of cosmetic manufacturers have used it for the high-priced anti-aging products. However it is easily oxidized in the air and the oxidation causes the side effects like the skin irritation and a poor delivery of the active ingredients into the skin. Thus the stability improvement of the retinol must be required to minimize the side effects and enhance the absorbability and moisturizing property of the final products. In this study, the derivatization of the retinol was performed to enhance the stability and the low-priced commercial retinol was used as the material to strengthen the competitiveness of the retinol based anti-aging products. Please click Additional Files below to see the full abstract

Related-Key Boomerang Attack on Block Cipher SQUARE

Square is 8-round SPN structure block cipher and its round function and key schedule have been slightly modified to design building blocks of Rijndael. Key schedule of Square is simple and efficient but fully affie, so we apply a related-key attack on it. We find a 3-round related-key differential trail with probability 2^28, which have zero differences both on its input and output states, and this trail is called the local collision in [5]. By extending of this related-key differential, we construct a 7-round related-key boomerang distinguisher and successful attack on full round Square. The best attack on Square have ever been known is the square attack on 6-round reduced variant of Square. In this paper, we present a key recovery attack on the full round of Square using a related-key boomerang distinguisher. We construct a 7-round related-key boomerang distinguisher with probability 2^119 by finding local collision, and calculate its probability using ladder switch and local amplification techniques. As a result, one round on top of distinguisher is added to construct a full round attack on Square which recovers 16-bit key information with 2^36 encryptions and 2^123 data

Preimage Attack on ARIRANG

The hash function ARIRANG is one of the 1st round SHA-3 candidates. In this paper, we present preimage attacks on ARIRANG with step-reduced compression functions. We consider two step-reduced variants of the compression function. First one uses the same feedforward$_1$ as the original algorithm, and the other one has the feedforward$_1$ working at the output of the half steps. Our attack finds a preimage of the 33-step OFF(Original FeedForward$_1$)-variants of ARIRANG-256 and ARIRANG-512 from Step 1 to Step 33, and a preimage of the 31-step MFF(Middle FeedForward$_1$)-variants of ARIRANG-256 and ARIRANG-512 from Step 3 to Step 33

Drying Effect on Enzymatic Hydrolysis of Cellulose Associated with Porosity and Crystallinity

The effect of drying on the enzymatic hydrolysis of cellulose was determined by analysis of porosity and crystallinity. Fiber hornification induced by drying produced an irreversible reduction in pore volume due to shrinkage and pore collapse, and the decrease in porosity inhibited enzymatic hydrolysis. The drying effect index (DEI) was defined as the difference in enzymatic digestibility between oven- and never-dried pulp, and it was determined that more enzymes caused a higher DEI at the initial stage of enzymatic hydrolysis and the highest DEI was also observed at the earlier stages with higher enzyme dosage. However, there was no significant difference in the DEI with less enzymes because cellulose conversion to sugars during hydrolysis did not enhance enzymatic hydrolysis due to the decrease in enzyme activity. The water retention value (WRV) and Simons’ staining were used to measure pore volume and to investigate the cause of the decrease in enzymatic hydrolysis. A decrease in enzyme accessibility induced by the collapse of enzymes’ accessible larger pores was determined and this decreased the enzymatic hydrolysis. However, drying once did not cause any irreversible change in the crystalline structure, thus it seems there is no correlation between enzymatic digestibility and crystalline structure

Rotational-XOR Rectangle Cryptanalysis on Round-Reduced Simon

Recently, Ashur and Liu introduced the Rotational-XOR-difference approach which is a modification of rotational cryptanalysis, for an ARX cipher Speck (Ashur and Liu, 2016). In this paper, we apply the Rotational-XOR-difference (RXD) approach to a non-ARX cipher Simon and evaluate its security. First, we studied how to calculate the probability of an RXD for bitwise AND operation that the round function of Simon is based on unlike Speck is on modular addition. Next, we prove that two RXD trails can be connected such that it becomes possible to construct a boomerang/rectangle distinguisher similar to the case using differential characteristics. Finally, we construct related-key rectangle distinguishers for round-reduced versions of Simon with block lengths of 32, 48, and 64, and we suggest a five- or six-round key recovery attack. To our knowledge, it is the first attempt to apply the notion of rotational cryptanalysis for a non-ARX cipher. Although our attack does not show the best results for Simon thus far, the attempt here to define and apply a new cryptanalytic characteristic is meaningful, and we expect further improvements and applications to other ciphers to be made in subsequent studies

Green and Sustainable Hot Melt Adhesive (HMA) Based on Polyhydroxyalkanoate (PHA) and Silanized Cellulose Nanofibers (SCNFs)

Polyhydroxyalkanoate (PHA), with a long chain length and high poly(4–hydroxybutyric acid) (P4HB) ratio, can be used as a base polymer for eco-friendly and biodegradable adhesives owing to its high elasticity, elongation at break, flexibility, and processability; however, its molecular structures must be adjusted for adhesive applications. In this study, surface-modified cellulose nanofibers (CNFs) were used as a hydrophobic additive for the PHA-based adhesive. For the surface modification of CNFs, double silanization using tetraethyl orthosilicate (TEOS) and methyltrimethoxysilane (MTMS) was performed, and the thermal and structural properties were evaluated. The hydrophobicity of the TEOS- and MTMS-treated CNFs (TMCNFs) was confirmed by FT-IR and water contact angle analysis, with hydrophobic CNFs well dispersed in the PHA. The PHA–CNFs composite was prepared with TMCNFs, and its morphological analysis verified the good dispersion of TMCNFs in the PHA. The tensile strength of the composite was enhanced when 10% TMCNFs were added; however, the viscosity decreased as the TMCNFs acted as a thixotropic agent. Adding TMCNFs to PHA enhanced the flowability and infiltration ability of the PHA–TMCNFs-based adhesive, and an increase in the loss tangent (Tan δ) and adjustment of viscosity without reducing the adhesive strength was also observed. These changes in properties can improve the flowability and dispersibility of the PHA–TMCNFs adhesive on a rough adhesive surface at low stress. Thus, it is expected that double-silanized CNFs effectively improve their interfacial adhesion in PHA and the adhesive properties of the PHA–CNFs composites, which can be utilized for more suitable adhesive applications

Catalytic Conversion of α-Pinene to High-Density Fuel Candidates Over Stannic Chloride Molten Salt Hydrates

The synthesis of dimeric products from monoterpene hydrocarbons has been studied for the development of renewable high-density fuel. In this regard, the conversion of α-pinene in turpentine over stannic chloride molten salt hydrates (SnCl4·5H2O) as a catalyst was investigated, and the reaction products were analyzed with gas chromatography/flame ionization detector/mass spectrometer (GC/FID/MS). Overall, the content of α-pinene in a reaction mixture decreased precipitously with an increasing reaction temperature. Almost 100% of the conversion was shown after 1 h of reaction above 90 °C. From α-pinene, dimeric products (hydrocarbons and alcohols/ethers) were mostly formed and their yield showed a steady increase of up to 61 wt% based on the reaction mixture along with the reaction temperature. This conversion was thought to be promoted by Brønsted acid activity of the catalyst, which resulted from a Lewis acid-base interaction between the stannic (Sn(IV)) center and the coordinated water ligands. As for the unexpected heteroatom-containing products, oxygen and chlorine atoms were originated from the coordinated water and chloride ligands of the catalyst. Based on the results, we constructed not only a plausible catalytic cycle of SnCl4·5H2O but also the mechanism of catalyst decomposition

Application of Sulfated Tin (IV) Oxide Solid Superacid Catalyst to Partial Coupling Reaction of α-Pinene to Produce Less Viscous High-Density Fuel

Brønsted acid-catalyzed reactions of α-pinene have been studied because of their ability to produce various types of fragrance molecules. Beyond this application, dimeric hydrocarbon products produced from coupling reactions of α-pinene have been suggested as renewable high-density fuel molecules. In this context, this paper presents the application of a sulfated tin(IV) oxide catalyst for the partial coupling reaction of α-pinene from turpentine. Brønsted acid sites inherent in this solid superacid catalyst calcined at 550 °C successfully catalyzed the reaction, giving the largest yield of dimeric products (49.6%) at 120 °C over a reaction time of 4 h. Given that the low-temperature viscosity of the mentioned dimeric products is too high for their use as a fuel in transportation engines, lowering the viscosity is an important avenue of study. Therefore, our partial coupling reaction of α-pinene provides a possible solution as a considerable amount of the isomers of α-pinene still remained after the reaction, which reduces the low-temperature viscosity. On the basis of a comparison of the reaction products, a plausible mechanism for the reaction involving coinstantaneous isomerization and coupling reaction of α-pinene was elucidated