Photometric determination of peracetic acid by reaction with potassium iodide solution.

Peracetic acid (PAA) is a strong oxidizing agent and is considered an ideal disinfectant because of its excellent disinfecting effect at low concentration, low corrosiveness, and relatively low cost. Commercially available PAA solution is a mixture of PAA, acetic acid, and hydrogen peroxide. However, PAA naturally decomposes faster than hydrogen peroxide. Therefore, accurately quantifying the concentration of PAA in the PAA peroxide mixture via a simple method is important. In the present study, a new method was developed, in which the spectral change of I- ion at 226 nm and the absorption value from the generated I2 at 460 nm were used to determine the concentration of PAA, following a chemical reaction with 0.1 mM potassium iodide (KI) solution without the use of any other chemicals. In this work, the measurable concentration of PAA was as low as 0.0001 wt% (13.1 µM) and as high as 0.0015 wt% (197.2 µM), which matches well with high linearity (99.95% at 226 nm and 99.91% at 460 nm). This work could also be the high selectivity method toward PAA in the PAA peroxide mixture.

A simple spectrophotometric determination of hydrogen peroxide solution via spectral delta from redox reaction with sodium hypochlorite.

Hydrogen peroxide (H2O2) is widely used in the synthesis of organic chemicals, bleaching of paper pulp, and the treatment of wastewater and as a food additive, important mediator of redox processes in natural water, and a disinfectant. However, H2O2 stock solution is unstable and slowly decomposes when exposed to, for example, light, elevated temperatures, or metal compounds. Therefore, the ability to measure the exact concentration of H2O2 stock solution is important for its proper use in diverse applications. This work proposes a simple method for the spectrophotometric determination of H2O2 solution via chemical reaction with sodium hypochlorite that is inexpensive and easy to acquire. The proposed method is based on the stoichiometric spectral change of hypochlorite ion at 292.5 nm following a redox reaction with a sample solution of H2O2. Due to high relationship between the spectral delta value and the applied H2O2 concentration (0.00188-0.03000%), H2O2 stock solution can be easily quantified.

Nonclinical safety evaluation of food colorant lac dye via systematic toxicity profiling with assessment of in vivo antigenic potential.

Lac dye is a natural colorant derived mainly from the insect Kerria lacca (Kerr) and has been used in food and beverage as a red-coloring additive. Despite its increasing use for human consumption as an alternative for allergy-associated cochineal, its toxicity profile remained incomplete to sufficiently assess its safety for the intended use. In this study, we evaluated systemic and genetic toxicity by performing acute and subacute oral toxicity studies in Sprague-Dawley (SD) rats using highly purified lac dye (LD) formulated in water and a battery of genotoxicity tests, respectively. To assess antigenic potentials, we carried out an in vivo passive cutaneous anaphylaxis test. A single dose of LD did not cause mortality at 5000 mg/kg body weight (BW), setting oral LD50 of >5000 mg/kg BW in SD rats. In the 90-day study, transient salivation without accompanying histopathological lesions in the salivary glands in 200 and 500 mg/kg BW groups and red-purple pigmentation on the surface of femora and skulls in 500 mg/kg groups were observed as nonadverse effects associated with LD, and no adverse effect was detected in all of the parameters examined, establishing a 500 mg/kg BW as no-observed-adverse-effect-level (NOAEL). Furthermore, LD was not mutagenic nor clastogenic in the genotoxicity tests. When tested for antigenicity, LD did not induce anaphylactic skin responses as opposed to the positive reaction by ovalbumin, suggesting a lack of antigenicity. Taken together, these findings provide extended toxicity information on LD with direct evidence supporting the lack of antigenicity, providing essential guidance for its safe use in humans.

Diagnosis and treatment of macrocytic anemia in a perinatal common marmoset: a case report.

BACKGROUND: The common marmoset is widely used in current biomedical research for various research fields. We observed macrocytic anemia in a perinatal common marmoset with gradual weight loss and diarrhea. The objective of this case report is to describe the diagnosis and treatment of macrocytic anemia in a perinatal common marmoset. CASE PRESENTATION: A 7-year-old female common marmoset showed clinical signs of gradual weight loss and intermittent diarrhea beginning 3 months after giving birth. Macrocytic anemia was diagnosed due to a decreased red blood cell (RBC) count, low hemoglobin level, and increased mean corpuscular volume (MCV). Multivitamins containing cobalamin and folate were administered for 7 days, and the patient's RBC count recovered to near the normal range with this treatment. CONCLUSIONS: Macrocytic anemia can be diagnosed by evaluating the MCV on a complete blood count (CBC) and cobalamin or folate levels and be treated by supplementation with cobalamin and folate. Such supplements may be needed during pregnancy and lactation in female common marmosets and/or in animals with chronic diarrhea.

Differential manifestation of ocular phenotypes in TALEN-mediated p19arf knockout FVB/N and C57BL/6J mouse lines.

BACKGROUND: p19arf, primarily known as a tumor suppressor, has also been reported to play an essential role in normal development of mouse eyes. Consistently, lack of p19arf has been associated with ocular defects, but the mixed background of the knockout (KO) mouse strain used raised a concern on the accuracy of the phenotypes observed in association with the targeted gene due to genetic heterogeneity. OBJECT: We carried out a study to investigate into the effect of genetic background on the manifestation of p19arf KO associated phenotypes. METHODS: We characterized the phenotypes of novel p19arf KO mouse lines generated in FVB/N and C57BL/6J using a transcription activator-like effector nuclease (TALEN) system in comparison to the reported phenotypes of three other p19arf-deficient mouse lines generated using homologous recombination. RESULTS: Ninety-five percent of FVB/N-p19arf KO mice showed ocular opacity from week 4 after birth which worsened rapidly until week 6, while such abnormality was absent in C57BL/6J-p19arf KO mice up to the age of 26 weeks. Histopathological analysis revealed retrolental masses and dysplasia in the retinal layer in FVB/N-p19arf KO mice from week 4. Besides these, both strains developed normally from birth to week 26 without increased tumorigenesis except for a subcutaneous tumor found in a C57BL/6J-p19arf KO mouse. CONCLUSION: Our findings demonstrated surprisingly variable manifestation of p19arf-linked phenotypes between FVB/N and C57BL/6J mice, and furthermore between our mouse lines and the established lines, indicating a critical impact of genetic background on functional study of genes using gene targeting strategies in mice.

CRISPR/Cas9-mediated knockout of CD47 causes hemolytic anemia with splenomegaly in C57BL/6 mice.

CD47 (integrin-associated protein), a multi-spanning transmembrane protein expressed in all cells including red blood cells (RBCs) and leukocytes, interacts with signal regulatory protein α (SIRPα) on macrophages and thereby inhibits phagocytosis of RBCs. Recently, we generated a novel C57BL/6J CD47 knockout (CD47 -/- hereafter) mouse line by employing a CRISPR/Cas9 system at Center for Mouse Models of Human Disease, and here report their hematological phenotypes. On monitoring their birth and development, CD47 -/- mice were born viable with a natural male-to-female sex ratio and normally developed from birth through puberty to adulthood without noticeable changes in growth, food/water intake compared to their age and sex-matched wild-type littermates up to 26 weeks. Hematological analysis revealed a mild but significant reduction of RBC counts and hemoglobin in 16 week-old male CD47 -/- mice which were aggravated at the age of 26 weeks with increased reticulocyte counts and mean corpuscular volume (MCV), suggesting hemolytic anemia. Interestingly, anemia in female CD47 -/- mice became evident at 26 weeks, but splenomegaly was identified in both genders of CD47 -/- mice from the age of 16 weeks, consistent with development of hemolytic anemia. Additionally, helper and cytotoxic T cell populations were considerably reduced in the spleen, but not in thymus, of CD47 -/- mice, suggesting a crucial role of CD47 in proliferation of T cells. Collectively, these findings indicate that our CD47 -/- mice have progressive hemolytic anemia and splenic depletion of mature T cell populations and therefore may be useful as an in vivo model to study the function of CD47.

MTF performance verification of an athermalized large-aperture IR optical system for space environment.

We develop an athermalized IR optical system operating in the temperature range of 10°C-30°C in vacuum. As large defocus errors can occur in IR optical systems in such an environment, we estimate the amount of defocus induced by the thermoelastic effect, thermo-optic effect, and air-to-vacuum transition. Furthermore, we measure the modulation transfer function (MTF) performance of our IR optical system in a thermal vacuum chamber. Our athermal system design and accurate estimation of the air-to-vacuum transition effect enable the realization of a stable IR optical system for a space environment, which exhibits an MTF value greater than 18%.

Nutrient intake and food restriction in children with atopic dermatitis.

This study was performed to investigate the status of food restriction and the list of restricted foods in children with moderate to severe atopic dermatitis (AD), and to find out the effect of food restriction on the changes in nutrient intake and the severity of the disease. Sixty two patient children aged 12 months to 13 years presenting AD with a SCORing of Atopic Dermatitis (SCORAD) index between 20 and 50 were enrolled. The presence of food limitation, and list of restricted foods were surveyed through the caretakers and the patients were divided into 3 groups by the number of restricted food: non-restricted group, one to three restricted group, and more than three restricted group. Dietary intake was assessed for 3 months using a food frequency questionnaire (FFQ). Half of the subjects restricted foods. The restriction was higher in the order of soda, food additives, walnut, peanut, and other nuts as a single food item; and shellfish and crustacean group, processed foods, nuts, milk & dairy products, and meats as a food group. More than three restricted group ingested more fruits and less fish and meats, resulting in high consumption of vitamin C (p = 0.027). No significant difference in the ratio of nutrient intake by the number of restricted foods was observed in other nutrients. Significant improvement of AD symptom was observed in non-restricted group (p = 0.036) and one to three restricted group (p = 0.003). It is necessary to provide proper nutrition information and systematic and continuous nutrition management for balanced nutrient intake and disease improvement in children with AD.

Effects of seed layers on structural, morphological, and optical properties of ZnO nanorods.

We studied the effects of seed layers on the structural and optical properties of ZnO nanorods. ZnO and Ag-doped ZnO (ZnO:Ag) seed layers were deposited on glass substrates by magnetron co-sputtering. ZnO nanorods were grown on these seed layers by the chemical bath deposition in an aqueous solution of Zn(NO3)2 and hexamethyltetramine. SEM micrographs clearly reveal that ZnO nanorods were successfully grown on both kinds of seed layers. The XRD patterns indicate that crystallization of ZnO nanorods is along the c-axis. Meanwhile, the packing density and the vertical alignment of the ZnO nanorods on the ZnO seed layer are better than those of the ZnO nanorods on ZnO:Ag. The enhanced growth of nanorods is thought to be due to the fact that the ZnO layer exhibits a higher crystalline quality than the ZnO:Ag layer. According to the low-temperature photoluminescence spectra, the ZnO nanorods on the ZnO seed layer show a narrow strong ultraviolet emission band centered at 369 nm, while those on ZnO:Ag exhibit multiple bands. These results are thought to be related with the crystallinity of ZnO nanorods, the morphologies of ZnO nanorods, and the reflectivities of seed layers. More detailed studies for clarification of the seed layer effect on the growth of ZnO nanorods are desirable.

New insights into ETS-10 and titanate quantum wire: a comprehensive characterization.

The titanate quantum wires in ETS-10 crystals remain intact during ion exchange of the pristine cations (Na(+)(0.47) + K(+)(0.53)) with M(n+) ions (M(n+) = Na(+), K(+), Mg(2+), Ca(2+), Sr(2+), Ba(2+), Pb(2+), Cd(2+), Zn(2+)) and during reverse exchange of the newly exchanged cations with Na(+). The binding energies of O(1s) and Ti(2p) decrease as the electronegativity of the cation decreases, and they are inversely proportional to the negative partial charge of the framework oxygen [-delta(O(f))]. At least five different oxygen species were identified, and their binding energies (526.1-531.9 eV) indicate that the titanate-forming oxides are much more basic than those of aluminosilicate zeolites (530.2-533.3 eV), which explains the vulnerability of the quantum wire to acids and oxidants. The chemical shifts of the five NMR-spectroscopically nonequivalent Si sites, delta(I(A)), delta(I(B)), delta(II(A)), delta(II(B)), and delta(III), shift downfield as -delta(O(f)) increases, with slopes of 2.5, 18.6, 133.5, 216.3, and 93.8 ppm/[-delta(O(f))], respectively. The nonuniform responses of the chemical shifts to -delta(O(f)) arise from the phenomenon that the cations in the 12-membered-ring channels shift to the interiors of the cages surrounded by four seven-membered-ring windows. On the basis of the above, we assign delta(I(A)), delta(I(B)), delta(II(A)), and delta(II(B)) to the chemical shifts arising from Si(12,12), Si(12,7), Si(7,12), and Si(7,7) atoms, respectively. The frequency of the longitudinal stretching vibration of the titanate quantum wire increases linearly and the bandwidth decreases nonlinearly with increasing -delta(O(f)), indicating that the titanate quantum wire resembles a metallic carbon nanotube. As the degree of hydration increases, the vibrational frequency shifts linearly to higher frequencies while the bandwidth decreases. We identified another normal mode of vibration of the quantum wire, which vibrates in the region of 274-280 cm(-1). In the dehydrated state, the band-gap energy and the first absorption maximum shift to lower energies as -delta(O(f)) increases, indicating the oxide-to-titanium(IV) charge-transfer nature of the transitions.

Structures of ionic liquids with different anions studied by infrared vibration spectroscopy.

We investigated the structures of ionic liquids (1-butyl-3-methylimidazolium iodide [BMIM][I] and 1-butyl-3-methylimidazolium tetrafluoroborate [BMIM][BF4]) and their aqueous mixtures using attenuated total reflection (ATR) infrared absorption and Raman spectroscopy. The ATR spectrum in the CHx (x = 1, 2, 3) vibration region from 2800 to 3200 cm-1 was very different between [BMIM][BF4] and [BMIM][I] even though all the spectral features in this region were from the butyl chain and the imidazolium ring of the same cation. The spectrum did not change appreciably irrespective of the water concentration for [BMIM][BF4], whereas the spectrum from [BMIM][I] showed significant changes as the water concentration was increased, especially in CH-vibration modes from the imidazolium ring. For very diluted solutions both aqueous mixtures of [BMIM][I] and [BMIM][BF4] showed very similar spectra. Mixing of [BMIM][I] with heavy water (D2O) facilitated the isotopic exchange of the proton attached to the most acidic carbon of the imidazolium ring into deuterium from D2O, whereas even prolonged exposure to D2O did not induce any isotopic exchange for [BMIM][BF4]. Raman spectra around 600 cm(-1) indicative of the butyl chain conformation also changed differently as the water concentration was increased between [BMIM][I] and [BMIM][BF4]. These differences are considered to come from the variation in the position of the anion, where I- is expected to be closer to the C(2) hydrogen of the imidazolium cation and interacting more specifically as compared to BF(4-).