21 Fluorescent Protein-Based DNA Staining Dyes.

Fluorescent protein-DNA-binding peptides or proteins (FP-DBP) are a powerful means to stain and visualize large DNA molecules on a fluorescence microscope. Here, we constructed 21 kinds of FP-DBPs using various colors of fluorescent proteins and two DNA-binding motifs. From the database of fluorescent proteins (FPbase.org), we chose bright FPs, such as RRvT, tdTomato, mNeonGreen, mClover3, YPet, and mScarlet, which are four to eight times brighter than original wild-type GFP. Additionally, we chose other FPs, such as mOrange2, Emerald, mTurquoise2, mStrawberry, and mCherry, for variations in emitting wavelengths. For DNA-binding motifs, we used HMG (high mobility group) as an 11-mer peptide or a 36 kDa tTALE (truncated transcription activator-like effector). Using 21 FP-DBPs, we attempted to stain DNA molecules and then analyzed fluorescence intensities. Most FP-DBPs successfully visualized DNA molecules. Even with the same DNA-binding motif, the order of FP and DBP affected DNA staining in terms of brightness and DNA stretching. The DNA staining pattern by FP-DBPs was also affected by the FP types. The data from 21 FP-DBPs provided a guideline to develop novel DNA-binding fluorescent proteins.

Development and validation of a dynamic mass-balance prediction model for indoor particle concentrations in an office room.

The Korean government recommends intermittent operation of air purifiers (APs) as a measure to maintain indoor particulate matter (PM) concentrations below the mandatory standards and reduce exposure to indr PM2.5 (PM with a diameter smaller than 2.5 µm). However, there is no guideline to inform occupants of when and how long APs should be operated to comply with the standards. In this study, we developed a dynamic mass-balance model to predict indoor PM concentrations in an office considering penetration of outdoor particles, change in number of occupants, and operational status of the AP. The model fit and prediction accuracies were verified using the American Society for Testing and Materials (ASTM) D 5157 criteria and the k-fold validation technique. We observed that indoor PM2.5 concentrations were determined by infiltration of outdoor PM2.5, and indoor generation/resuspension by occupants and removal. For PM2.5-10(2.5 µm

Improved Performance of High Energy Materials Based on Dinitramide Salts and Its Liquid Monopropellant.

As an eco-friendly alternative fuel material, ammonium dinitramide (ADN, NH4N(NO2)2) is safe and stable at room temperature; however, it requires high purity for practical applications. A small amount of impurities can retard the catalytic decomposition of the monopropellant in the thruster, lower the specific impulse, and induce side effects such as clogging of the nozzle. Therefore, we purified NH4N(NO2)2 by performing repeated extractions, adsorption by powdered activated carbon, and low-temperature extractions. In this study, we evaluated the chemical density of purified NH4N(NO2)2 through Fourier-transform infrared spectroscopy, ultraviolet-visible spectroscopy, and ion chromatography, and obtained a final purity of 99.8%. Furthermore, we fabricated a liquid fuel using high-purity NH4N(NO2)2 as the main oxidizing agent, and can be prepared a mono-propellant formulation that exhibited decomposition at a minimum temperature of 148 °C.

Characterization and source identification of fine dust in Seoul elementary school classrooms.

To evaluate the level of fine particulate matters in elementary schools located in a high traffic area of Seoul and verify the emission source, a field study on the classrooms was conducted under the uncontrolled condition. The indoor PM2.5 was lower than that of the outdoors as indicated by an I/O ratio of 0.52-0.92 based on mass concentration, and it was maintained below the National Guideline. Heavy metals such as Cr, Mn, Ni, Cu, Zn, As, Sn and Pb were lower in indoor PM2.5 than outdoors. On the contrary, carbons including OC and EC were higher in indoor PM2.5. As a result of source apportionment analysis, an outdoor emission source was responsible for 58.5% of the classroom PM2.5. This study can contribute to urban planning and school design to keep children safe from harmful environments.

Catalytic Decomposition of Energetic Liquid Solution Over Various Types of Hexaaluminate Catalysts.

A hexaaluminate support was prepared by a co-precipitation method, and a metal (Cu, Pt, or Ir) was impregnated on the support to prepare a powdered catalyst. After that, organic and inorganic binders were added to the powdery catalyst and then pellets were formed. The so-formed catalysts were heat-treated at 1200°C, and their physicochemical properties were analyzed by N2-adsorption, X-ray diffraction (XRD), X-ray fluorenscence (XRF), and scanning electron microscopy (SEM). The decomposition activity of the catalysts on an ammonium dinitramide (ADN)-based liquid propellant was evaluated repeatedly, and the effects of catalyst composition and morphology on low temperature decomposition activity and durability were investigated. It was confirmed that the Cu-hexa-pellet, Pt-hexa-pellet, and Ir-hexa-pellet catalysts could be recovered and reused as a catalyst for decomposition of an ADN-based liquid monopropellant. The initial activity and the thermal stability of the Cu-hexa-pellet catalyst for the decomposition of ADN-based liquid monopropellants were better than for the other catalysts. The better activity of the Cu-hexa-pellet catalyst seems to be because the dispersion of the copper was higher than the metal dispersion in the other two catalysts.

Catalytic Decomposition of an Ionic Liquid Monopropellant Over Ir/Hexaaluminate Catalysts.

The aim of this study is to elucidate the influence of an iridium loading strategy over hexaaluminate on the catalytic performance during the decomposition of liquid monopropellants based on ammonium dinitramide (ADN). Powder-type and pellet-type Ir/hexaaluminate catalysts were prepared and their chemico-physical properties were characterized by N2 adsorption, XRD, XRF, and SEM. There were considerable differences in the Ir amounts present on the surface according to the impregnation method employed. The catalytic activities of three types of Ir/hexaaluminate catalysts to decompose the ADN-based liquid monopropellant were compared using a semi-batch type of reactor. Pellet-type Ir/hexaaluminate catalyst, which formed hexaaluminate into a pellet and where iridium was impregnated during the last stage, showed the lowest onset temperature during the decomposition of the ADN-based liquid monopropellant, having the effect of lowering the decomposition onset temperature by around 60 °C compared to that without a catalyst. This was due to the pellet-type Ir/hexaaluminate having a larger surface area and a large number of Ir active sites on its surface.

Ordered Mesoporous Cu-Mn Metal Oxides for the Catalytic Decomposition of an Energetic Ionic Liquid.

Ordered mesoporous Cu-Mn binary metal oxide (meso-CuMnOx) catalysts were successfully synthesized by a hard-templating method from a mesoporous silica template with a cubic Ia3d mesostructure (KIT-6) or hydrophobic KIT-6, exhibiting a well-developed crystalline framework, a regular pore size distribution and a high surface area. The copper and manganese elements in the mesoporous Cu-Mn binary metal oxides (meso-CuMnOx-N and meso-CuMnOx-HP), obtained from the KIT-6 and hydrophobic KIT-6, respectively, were homogeneously dispersed in the whole particles. The activities of meso-CuMnOx catalysts for the decomposition of a liquid monopropellant containing an energetic ionic liquid, ammonium dinitramide, were much higher than that over a CuMnOx catalyst prepared by a conventional precipitation method. This is attributed to the well-developed mesoporosity of the meso-CuMnOx catalysts. Among the mesoporous CuMnOx catalysts, the decomposition onset temperature over meso-CuMnOx-HP (87.9 °C) was found to be lower than that over meso-CuMnOx-N (100.4 °C), probably due to its higher mesoporosity and surface area.

Preparation of Mesoporous CuCe-Based Ternary Metal Oxide by Nano-Replication and Its Application to Decomposition of Liquid Monopropellant.

Mesoporous CuCe-based ternary metal oxides were synthesized using KIT-6 as a hard template through a nano-casting method. The mesoporous CuCe-based metal oxides were applied to the catalytic decomposition of the ammonium dinitramide-based liquid monopropellant. The decomposition onset temperature over the meso-CuCe ternary metal oxides was much lower than that over the CuCeOx catalyst prepared by conventional precipitation method. Higher activity of the meso-CuCe ternary metal oxides is attributed to higher surface area and larger pore size of the meso-CuCe ternary metal oxides than those of the conventional CuCe oxide. The highest activity of meso-CuCeZr catalyst among the meso-CuCe ternary metal oxide catalysts is likely due to the highest mesoporosity.

Successful Spontaneous Conception and Live Birth in a Woman with an Extremely Low Level of Anti-Müllerian Hormone Who Received Korean Herbal Medicine (Bogungsamul-tang): A Case Report.

Conventional treatments do not appreciably improve fecundity in women with extremely low-serum levels of anti-Müllerian hormone (AMH). In Korea, herbal medicine is widely used to treat female infertility. We report a case in which an infertile woman with a very low AMH level naturally conceived after two months of herbal treatment (Bogungsamul-tang), ultimately giving birth to a full-term baby. Although AMH levels were not measured immediately before and after treatment, our study suggests that Korean herbal remedies are a viable option for infertile women with negligible AMH levels. Further studies should be performed to fully assess the clinical effects of Bogungsamul-tang in such women.

The effect of intravenous labetalol administration on hemodynamic responses during desflurane inhalation.

BACKGROUND: Inspired concentrations of desflurane ≥ 1 minimum alveolar anesthetic concentration (MAC) have been related to sympathetic stimulation such as hypertension and tachycardia. The current study examined whether labetalol, an α(1) and ß-adrenergic antagonist would blunt these hemodynamic responses. METHODS: Fifty-four ASA physical status I patients, aged 20-60 years, were enrolled in this study. The patients were randomly divided into 2 groups. The breathing circuit was primed with an end-tidal desflurane concentration of 1.2 MAC in 6 L/min O(2). Normal saline 5 ml or labetalol 0.3 mg/kg was injected into groups S and L respectively. After 5 minutes, anesthesia was induced with intravenous etomidate 0.2 mg/kg and vecuronium 0.1 mg/kg. Each patient inhaled desflurane through a tight fitting facemask. Heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP) and end-tidal concentration of desflurane (et-des) were measured at 5 minutes after saline or labetalol injection (baseline) and every 1 minute for 5 minutes after desflurane inhalation and for 2 minutes after intubation. RESULTS: In the saline injection group (group S), desflurane inhalation increased heart rate and blood pressure, while labetalol 0.3 mg/kg attenuated the heart rate and blood pressure increase in group L. After tracheal intubation, heart rate and blood pressure were significantly lower in group L than in group S. CONCLUSIONS: These results demonstrate that administration of intravenous labetalol is effective in attenuating tracheal intubation and desflurane-induced hemodynamic responses.