Prostaglandin E receptor subtypes in mouse osteoblastic cell line

PGE2 is one of the key molecules in the osteoblast. It is the major prostanoid in the bone, and its production is under the control of both systemic and local factors. PGE2 has been reported to have multiple actions in the osteoblast, such as growth promotion and cell differentiation. To better understand the action of PGE2 in the osteoblast, we determined the PGE receptor subtypes in MC3T3-E1, an osteoblastic cell line derived from the normal mouse calvaria. Northern blot analysis revealed that EP1 and EP4 subtypes are expressed in MC3T3-E1. In contrast, EP3 subtype was not detected by either Northern blot analysis or RT-PCR. The contribution of each subtype was evaluated by studying the effects of subtype-specific analogs on osteoblastic function at confluency and 5 days after confluency. An EP1 agonist, 17-phenyl-omega-trinor PGE2, increased DNA synthesis and decreased alkaline phosphatase activity. 11-Deoxy-PGE1, and EP2 and EP4 agonist, decreased DNA synthesis and increased alkaline phosphatase activity at both stages. Butaprost, an EP2-selective agonist, showed effects similar to those of 11-deoxy-PGE1 only at confluency. Another and more differentiated osteoblastic marker, osteocalcin production, was detectable and was stimulated by 11-deoxy-PGE1 only 5 days after confluency. The exposure of these cells to EP1 agonist changed the cell shape to a more fibroblastic appearance. These results indicate that EP1, EP4, and probably EP2 are present in MC3T3-E1 cells; EP1 promotes cell growth, and EP2 and EP4 mediate differentiation of the osteoblast. Furthermore, the decreased response to EP2-specific agonist 5 days after confluency suggests that the expression of PGE receptor subtype is dependent on the stage of osteoblastic differentiation. This is the first report to determine PGE receptor subtypes in the bone.     

Formation of phase structure and crystallization behavior in blends containing polystyrene–polyethylene block copolymers

The microphase separation structure in the molten state and the structure formation in crystallization from such ordered melt were investigated for the blends of polystyrene–polyethylene block copolymers (SE) with polystyrene homopolymer (PS) and polyethylene homopolymer (PE) and for the blends consisting of two kinds of SE with different copolymer compositions from each other, using synchrotron small-angle X-ray scattering techniques (SAXS). The copolymer compositions of SE block copolymers employed were 0.34, 0.58 and 0.73 wt. fraction of PE, and their melt morphologies were cylindrical, lamellar and lamellar, respectively. Macrophase separation or the morphology change in the melt occurred depending on the molecular weight and the blend composition, as reported so far. In crystallization from such macrophase-separated and microphase-separated melts, the melt morphology was completely kept for all the blends. Crystallization behavior was also investigated for the blends. The crystallization within the spherical and cylindrical domains surrounded by glassy PS was not observed for SE/PS blends. In the crystallization from the macrophase-separated melt, two exothermal peaks were observed in the DSC measurements, while a single peak was observed for other blends. For the blends with PS, the degree of crystallinity was depressed and the apparent activation energy of crystallization was high, compared to those for the corresponding neat SE. For SE/PE and SE/SE blends, those were changed depending on the blend composition.     

Modeling of quantitative relationships between physicochemical properties of active pharmaceutical ingredients and tensile strength of tablets using a boosted tree

Objectives: The aim of this study was to explore the potential of boosted tree (BT) to develop a correlation model between active pharmaceutical ingredient (API) characteristics and a tensile strength (TS) of tablets as critical quality attributes.

Methods: First, we evaluated 81 kinds of API characteristics, such as particle size distribution, bulk density, tapped density, Hausner ratio, moisture content, elastic recovery, molecular weight, and partition coefficient. Next, we prepared tablets containing 50% API, 49% microcrystalline cellulose, and 1% magnesium stearate using direct compression at 6, 8, and 10?kN, and measured TS. Then, we applied BT to our dataset to develop a correlation model. Finally, the constructed BT model was validated using k-fold cross-validation.

Results: Results showed that the BT model achieved high-performance statistics, whereas multiple regression analysis resulted in poor estimations. Sensitivity analysis of the BT model revealed that diameter of powder particles at the 10th percentile of the cumulative percentage size distribution was the most crucial factor for TS. In addition, the influences of moisture content, partition coefficients, and modal diameter were appreciably meaningful factors.

Conclusions: This study demonstrates that BT model could provide comprehensive understanding of the latent structure underlying APIs and TS of tablets.     

Visualization of TiO2 Reduction Behavior in Molten Salt Electrolysis

Metallurgical and Materials Transactions B - An in situ observation technique of the TiO2 interfacial behavior in molten LiCl-KCl electrolysis was developed. The variation of the thin TiO2...     

Acoustic recognition of counterions in ion-exchange resins

In a coupled acoustic-gravity field, particles are aggregated at a particular position determined by their acoustic properties, such as density and compressibility. The observation of the aggregation of cation-exchange resin particles in this field has confirmed that the types of countercations strongly affect the behavior of the particles. Detailed analyses have revealed that the different behavior comes not from the density of the resins but from their compressibility as far as H+- and NBu4+-form cation-exchange resins are concerned. Since these resins are aggregated at the different positions, we can gain information of counterions from aggregation coordinates. Counterions can thus be recognized through the observation of the aggregation behavior of resin particles in the field without chemical analyses routinely employed in ion-exchange studies.     

Electrochemical behavior of Al in a non-aqueous alkyl carbonate solution containing LiBOB salt

Aluminum was studied as a current collector for rechargeable lithium batteries to understand electrochemical and passivation behavior. Electrochemical polarization tests, in situ scratch polarization tests and time-of-flight secondary ion mass spectroscopy (ToF-SIMS) analysis in lithium bis-oxalato borate (LiBOB)-containing alkyl carbonate solution were conducted. The Al foil did not follow the alloy and de-alloy process with the LiBOB salt in electrolyte at 0 V vs. Li/Li⁺ in the cathodic sweep. During the anodic scan to the noble direction, the absence of an oxidation peak up to 3 V vs. Li/Li⁺ indicated that the air-formed oxide layer of Al was not reduced to metal. Oxide-free Al surfaces made by the in situ scratch test during the electrochemical polarization resulted in abrupt alloy formation with Li at 0 V vs. Li/Li⁺, but the newly formed surface formed passive films at higher potential with oxygen, namely, Al-O compound, as confirmed by ToF-SIMS.     

Atmospheric outflow of anthropogenic semivolatile organic compounds from East Asia in spring 2004

To estimate the emissions of anthropogenic semivolatile organic compounds (SOCs) from East Asia and to identify unique SOC molecular markers in Asian air masses, high-volume air samples were collected on the island of Okinawa, Japan between 22 March and 2 May 2004. Contributions from different source regions (China, Japan, the Koreas, Russia, and ocean/local) were estimated by use of source region impact factors (SRIFs). Elevated concentrations of hexachlorobenzene (HCB), hexachlorcyclohexanes (HCHs), dichlorodiphenyltrichloroethanes (DDTs), and particulate-phase polycyclic aromatic hydrocarbons (PAHs) were attributed to air masses from China. A large proportion of the variation in the current-use pesticides, gas-phase PAHs, and polychlorinated biphenyl (PCB) concentrations was explained by meteorology. Chlordanes showed a technical mixture profile and similar concentrations regardless of source region. alpha/gamma HCH and trans/cis chlordane ratios did not vary significantly with different source regions and had regional averages of 2.5 +/- 1.0 and 1.2 +/- 0.3, respectively. Particulate-phase PAH concentrations were significantly correlated (p value < 0.05) with other incomplete combustion byproduct concentrations, including elemental mercury (Hg0), CO, NOx, black carbon, submicrometer aerosols, and SO2. By use of measured PAH, CO, and black carbon concentrations and estimated CO and black carbon emission inventories, the emission of six carcinogenic particulate-phase PAHs was estimated to be 1518-4179 metric tons/year for Asia and 778-1728 metric tons/year for China, respectively. These results confirm that East Asian outflow contains significant emissions of carcinogenic particulate-phase PAHs.     

Contribution of brominated organic disinfection by-products to the mutagenicity of drinking water.

The activity inducing chromosomal aberrations of the mixture of brominated disinfection by-products (DBPs) was approximately three times higher than that of the chlorinated counterparts for the same hypohalous acid dose. With the combination of chromosomal aberration test and a new analytical technique to differentiate total organic chlorine (TOCl) and total organic bromine (TOBr), it was found that TOBr was correlated to the mutagenicity of chlorinated waters. It was also implied that for a bromide-to-TOC ratio of 0.1 (mg/mg C), brominated DBPs could account for at least 29% of the total toxicity of DBPs formed during chlorination. On the other hand, bromate ion, a major ozonation DBP, was not a major contributor to the activity inducing chromosomal aberrations of the water treated with an ozone/chlorine sequential process. Therefore, ozonation is one possible option to reduce the health risk caused by DBPs even in the presence of bromide.     

High performance electron negative resist,chloromethylated polystyrene. A study on molecular parameters

High sensitivity and high contrast electron negative resist, chloromethylated polystyrene (CMS) was developed for direct writing electron beam lithography with 1-μm resolution. The resist shows excellent lithographic performances such as high plasma-etching durability and negligible “post polymerization effect”. A series of CMS covering a wide range of M?_w, 6,800–560,000, were synthesized by the chloromethylation of nearly monodisperse polystyrenes. The effects of molecular parameters on sensitivity and resolution were investigated. The chloromethylation remarkably improved the reactivity of polystyrene, but which was saturated above 40% of chloromethylation ratio. About 100 times higher sensitivity could be achieved as compared with the starting material. As the increase of chloromethylation ratio (CR) gradually broadened the molecular weight distribution (MWD), the optimum CR was evaluated to be about 40%. In the above range of M?_w, the sensitivity varies from 39 to 0.4 μC/cm, whereas the γ-value varies from 3.0 to 1.4. A sharp edge profile was obtained in developed pattern of CMS resist because of its relatively high glass-transition temperature (68–115°C) compared with commercial resists and the suitable selection of a developer. The resolution of CMS was compared with the structually related polymers synthesized from polystyrene with a broader MWD or vinylbenzylchloride and poly(chloroethylvinylether) (CEVE). These polymers show significantly lower resolution than CMS, which indicates the importance of MWD and T_g in electron negative resist.     

Electrochemical evaluation of the interaction between endocrine disrupter chemicals and estrogen receptor using 17,beta-estradiol labeled with daunomycin

A new electrochemical screening method for endocrine disrupting chemicals (EDCs) was developed. To evaluate the binding capacity of EDCs to the estrogen receptor (ER), 17beta-estradiol labeled with daunomycin as an electroactive compound was prepared. The electrochemical sensitivity of the prepared labeled estradiol (LE) was high, as compared with daunomycin. The interaction between LE and ER was observed by the decrease in the electrode response of LE, indicating the specific binding of LE with ER. The competitive reaction between LE and 17beta-estradiol for the limiting binding site on ER produced increases in the peak current of LE. The relative standard deviation at 1 x 10(-8) M 17beta-estradiol was about 10.0% (n = 7). The binding affinity between EDC and ER was also evaluated by comparison with 17beta-estradiol-ER interaction. Bisphenol A, p-nonylphenol and p,p'-DDT was used as a test compound. All test compounds demonstrated some ability to bind with ER. This electrochemical binding assay illustrates a new method for evaluating the binding capacity of EDCs to ER without the need for a separation procedure for the bound and free LE.