Effect of surface properties of silica nanoparticles on their cytotoxicity and cellular distribution in murine macrophages

In this study, complexes composed of poly-l-tyrosine (pLT) and single-walled carbon nanotubes (SWCNTs) were produced and the dispersibility of the pLT/SWCNT complexes in water by measuring the ζ potential of the complexes and the turbidity of the solution were investigated. It is found that the absolute value of the ζ potential of the pLT/SWCNT complexes is as high as that of SWCNTs modified with double-stranded DNA (dsDNA) and that the complexes remain stably dispersed in the water at least for two weeks. Thermogravimetry analysis (TGA) and visualization of the surface structures of pLT/SWCNT complexes using an atomic force microscope (AFM) were also carried out.     

C57BL/KsJ-db/db-Apc Mice Exhibit an Increased Incidence of Intestinal Neoplasms

The numbers of obese people and diabetic patients are ever increasing. Obesity and diabetes are high-risk conditions for chronic diseases, including certain types of cancer, such as colorectal cancer (CRC). The aim of this study was to develop a novel animal model in order to clarify the pathobiology of CRC development in obese and diabetic patients. We developed an animal model of obesity and colorectal cancer by breeding the C57BL/KsJ-db/db (db/db) mouse, an animal model of obesity and type II diabetes, and the C57BL/6J-Apc(Min/+) (Min/+) mouse, a model of familial adenomatous polyposis. At 15 weeks of age, the N9 backcross generation of C57BL/KsJ-db/db-Apc(Min/+) (db/db-Min/+) mice developed an increased incidence and multiplicity of adenomas in the intestinal tract when compared to the db/m-Min/+ and m/m-Min/+ mice. Blood biochemical profile showed significant increases in insulin (8.3-fold to 11.7-fold), cholesterol (1.2-fold to 1.7-fold), and triglyceride (1.2-fold to 1.3-fold) in the db/db-Min/+ mice, when compared to those of the db/m-Min/+ and m/m-Min/+ mice. Increases (1.4-fold to 2.6-fold) in RNA levels of insulin-like growth factor (IGF)-1, IRF-1R, and IGF-2 were also observed in the db/db- Min/+ mice. These results suggested that the IGFs, as well as hyperlipidemia and hyperinsulinemia, promoted adenoma formation in the db/db-Min/+ mice. Our results thus suggested that the db/db-Min/+ mice should be invaluable for studies on the pathogenesis of CRC in obese and diabetes patients and the therapy and prevention of CRC in these patients.     

Transferred arc plasma processed mullite from coal ash and bauxite

Coal ash disposal is one of the main problems in thermal power plant unit. Currently, a number of waste management systems are being tried for effective disposal of coal ash. In this paper, coal ash from thermal power plant unit was successfully utilized for synthesis of mullite ceramic by using transferred arc plasma processing (TAP) technique. For this purpose, bauxite was added with coal ash by 0, 25, 50 and75 weight ratio. The compositions were thoroughly mixed by ball milling and were melted in the transferred arc plasma torch at 10 kW input power level for 3 min. Argon was used as plasma forming gas. The phase and microstructure formation of the melted samples were investigated by XRD and SEM images. The results show that the additions of bauxite greatly influenced the phase formation of mullite during the processes.     

Preparation of surfactant-free vinyl polymers by conventional emulsion polymerization using hydrolysable emulsifiers

Emulsion polymerizations of several vinyl monomers, styrene, methyl methacrylate, butyl methacrylate, butyl acrylate, and vinyl acetate, in water using alkali–hydrolysable cationic surfactants with a betaine ester group (1-alkoxycarbonylmethyl)trimethylammonium chlorides, as emulsifiers were carried out and properties of the resulting latices and the polymers recovered by hydrolysis and salting out were investigated. There were little influences of the surfactants and monomers used here on the polymerizations, forming stable and monodisperse latices with a mean diameter of ca. 70 nm and giving a high molecular weight of polymers at high yields. All polymers were precipitated and recovered by adding a small amount of sodium hydroxide into the latex solutions contained little amount of ionic species. Solvent-cast films of the polymers were found to have surfaces as hydrophobic as those for the corresponding pure polymers prepared by bulk polymerization.     

Electrochemical properties of N-doped hydrogenated amorphous carbon films fabricated by plasma-enhanced chemical vapor deposition methods

Nitrogen-doped hydrogenated amorphous carbon thin films (a-C:N:H, N-doped DLC) were synthesized with microwave-assisted plasma-enhanced chemical vapor deposition widely used for DLC coating such as the inner surface of PET bottles. The electrochemical properties of N-doped DLC surfaces that can be useful in the application as an electrochemical sensor were investigated. N-doped DLC was easily fabricated using the vapor of nitrogen contained hydrocarbon as carbon and nitrogen source. A N/C ratio of resulting N-doped DLC films was 0.08 and atomic ratio of sp³/sp²-bonded carbons was 25/75. The electrical resistivity and optical gap were 0.695 Ω cm and 0.38 eV, respectively. N-doped DLC thin film was found to be an ideal polarizable electrode material with physical stability and chemical inertness. The film has a wide working potential range over 3 V, low double-layer capacitance, and high resistance to electrochemically induced corrosion in strong acid media, which were the same level as those for boron-doped diamond (BDD). The charge transfer rates for the inorganic redox species, Fe^2+/3+ and Fe(CN)₆^4−/3− at N-doped DLC were sufficiently high. The redox reaction of Ce^2+/3+ with standard potential higher than H₂O/O₂ were observed due to the wider potential window. At N-doped DLC, the change of the kinetics of Fe(CN)₆^3−/4− by surface oxidation is different from that at BDD. The rate of Fe(CN)₆^3−/4− was not varied before and after oxidative treatment on N-doped DLC includes sp² carbons, which indicates high durability of the electrochemical activity against surface oxidation.     

Molecular Features and Clinical Management of Hereditary Gynecological Cancers

Hereditary gynecological cancers are caused by several inherited genes. Tumors that arise in the female reproductive system, such as ovaries and the uterus, overlap with hereditary cancers. Several hereditary cancer-related genes are important because they might lead to therapeutic targets. Treatment of hereditary cancers should be updated in line with the advent of various new methods of evaluation. Next-generation sequencing has led to rapid, economical genetic analyses that have prompted a concomitant and significant paradigm shift with respect to hereditary cancers. Molecular tumor profiling is an epochal method for determining therapeutic targets. Clinical treatment strategies are now being designed based on biomarkers based on tumor profiling. Furthermore, the National Comprehensive Cancer Network (NCCN) guidelines significantly changed the genetic testing process in 2020 to initially consider multi-gene panel (MGP) evaluation. Here, we reviewed the molecular features and clinical management of hereditary gynecological malignancies, such as hereditary breast and ovarian cancer (HBOC), and Lynch, Li–Fraumeni, Cowden, and Peutz–Jeghers syndromes. We also reviewed cancer-susceptible genes revealed by MGP tests.     

The dilute solution properties of maleic anhydride and maleic acid copolymers: 1. Light scattering, osmotic pressure and viscosity measurements

Dilute solution behaviour of poly(maleic anhydride-co-ethyl vinyl ether) and poly(maleic acid-co-ethyl vinyl ether) has been investigated by light scattering, osmotic pressure, and viscosity measurements. The molecular weights ($\text{M}\text{?}{}_{\mathrm{w}}$ and $\text{M}\text{?}{}_{\mathrm{n}}$), the second virial coefficients A₂, and the intrinsic viscosities [η] have been determined for three states of this copolymer: anhydride-form, H-form, and Na-salt independently. The constants in the Mark-Houwink relations were obtained for the above three states under different solvent conditions. The molecular weight of the anhydride-form is found to be higher than that of the acid-form or the Na-salt, suggesting the degradation in a process of hydrolysis. The second virial coefficient A₂ as well as the Mark-Houwink relation indicates that the anhydride-form and H-form behave as flexible polymer chains in good solvents. However, the polymer coil of Na-salt is highly expanded even at saturated NaCl concentration.     

Graft copolymerization of styrene onto cellulose acetate p-nitrobenzoate by chain transfer reaction

Styrene was grafted onto cellulose acetate p-nitrobenzoate (CANB) by chain transfer reaction of growing polymer radicals to the pendant nitro groups of CANB. A copolymer with a branch for every 17.2 nitro groups was obtained. This result indicates that the pendant aromatic nitro group is more effective in obtaining a graft copolymer by radical mechanism than pendant double bond on the trunk polymer previously reported, where graft copolymers with a branch for several hundred of double bonds are produced.