UV–vis absorption spectroscopic study for on-line monitoring of uranium concentration in LiCl–KCl eutectic salt

UV–vis absorption spectroscopy of uranium in LiCl–KCl eutectic salt at 773 K was studied for the on-site use in pyrochemical process. Uranium(III) chloride was electrochemically prepared from uranium metal in LiCl–KCl eutectic salt at 773 K by using chronopotentiometry. Three absorption peak positions were selected and calibrated for the quantitative analysis of uranium in the molten salt medium. The molar absorptivity and minimum detectable concentration for the selected wavelength were obtained with a confidence level of 99%.     

A Kirkwood-Buff Derived Force Field for Aqueous Alkali Halides

A classical nonpolarizable force field is presented for the simulation of aqueous alkali halide solutions (MX), where M = Li(+), Na(+), K(+), Rb(+), Cs(+) and X = F(-), Cl(-), Br(-), I(-), and their interactions with biomolecules. The models are specifically designed to reproduce the experimental Kirkwood-Buff integrals, and thereby the solution salt activities, as a function of salt concentration. Additionally, we demonstrate that these models reasonably reproduce other experimental properties including ion diffusion constants, dielectric decrements, and the excess heats of mixing. The parameters are developed by considering the properties of aqueous NaX and MCl solutions using a previously established model for NaCl. Transferability of the parameters to other salts is then established by the successful simulation of additional aqueous salt solutions, KI and CsBr, not originally included in the parameterization procedure.     

Reduction of amine N-oxides by diboron reagents

Facile reduction of alkylamino-, anilino-, and pyridyl-N-oxides can be achieved via the use of diboron reagents, predominantly bis(pinacolato)- and in some cases bis(catecholato)diboron [(pinB)(2) and (catB)(2), respectively]. Reductions occur upon simply mixing the amine N-oxide and the diboron reagent in a suitable solvent, at a suitable temperature. Extremely fast reductions of alkylamino- and anilino-N-oxides occur, whereas pyridyl-N-oxides undergo slower reduction. The reaction is tolerant of a variety of functionalities such as hydroxyl, thiol, and cyano groups, as well as halogens. Notably, a sensitive nucleoside N-oxide has also been reduced efficiently. The different rates with which alkylamino- and pyridyl-N-oxides are reduced has been used to perform stepwise reduction of the N,N'-dioxide of (S)-(-)-nicotine. Because it was observed that (pinB)(2) was unaffected by the water of hydration in amine oxides, the feasibility of using water as solvent was evaluated. These reactions also proceeded exceptionally well, giving high product yields. In constrast to the reactions with (pinB)(2), triethylborane reduced alkylamino-N-oxides, but pyridine N-oxide did not undergo efficient reduction even at elevated temperature. Finally, the mechanism of the reductive process by (pinB)(2) has been probed by (1)H and (11)B NMR.     

AGR2, a mucinous ovarian cancer marker, promotes cell proliferation and migration

Ovarian cancer is a leading cause of death in women. Early detection of ovarian cancer is essential to decrease mortality. However, the early diagnosis of ovarian cancer is difficult due to a lack of clinical symptoms and suitable molecular diagnostic markers. Thus, identification of meaningful tumor biomarkers with potential clinical application is clearly needed. To search for a biomarker for the early detection of ovarian cancer, we identified human anterior gradient 2 (AGR2) from our systematic analysis of paired normal and ovarian tumor tissue cDNA microarray. We noted a marked overexpression of AGR2 mRNA and protein in early stage mucinous ovarian tumors compared to normal ovarian tissues and serous type ovarian tumors by Western blot analysis and immunohistochemistry. To further elucidate the role of AGR2 in ovarian tumorigenesis, stable 2774 human ovarian cancer cell lines overexpressing AGR2 were established. Forced expression of AGR2 in 2774 cells enhanced the growth and migration of ovarian cancer cells. AGR2 protein was detected in the serum of mucinous ovarian cancer patients by Western blot and ELISA analysis. Thus, AGR2 is a potential biomarker for the diagnosis of mucinous ovarian cancer and an ELISA assay may facilitate the early detection of mucinous ovarian cancer using patient serum.     

Suppression of hepatic tumor growth and metastasis by metronomic therapy in a rat model of hepatocellular carcinoma

Although continuous low-dose (metronomic [MET]) therapy exerts anti-cancer efficacy in various cancer models, the effect of long-term MET therapy for hepatocellular carcinoma (HCC) remains unknown. This study assessed the long-term efficacy of MET on suppression of tumor growth and spontaneous metastasis in a rat model of HCC induced by administration of diethylnitrosamine for 16 wk. The rats were divided into 3 groups: MTD group received intraperitoneal (i.p.) injections of 40 mg/kg cyclophosphamide on days 1, 3, and 5 of a 21-day cycle; Control and MET groups received i.p. injections of saline and 20 mg/kg cyclophosphamide twice a week, respectively. Anti-tumor and anti-angiogenic effects and anti-metastatic mechanisms including matrix metalloproteinases (MMPs) and tissue inhibitors of MMPs (TIMPs) were evaluated. Twelve wk of MET therapy resulted in a significant reduction in intrahepatic tumors than control or MTD therapy. The MET group had fewer proliferating cell nuclear antigen-positive cells and decreased hypoxia-inducible factor-1α levels and microvessel density. Lung metastases were detected in 100%, 80%, and 42.9% in the control, MTD, and MET groups, respectively. MET therapy significantly decreased expression of TIMP-1, MMP-2 and -9. For mediators of pro-MMP-2 activation, MET therapy induced significant suppression in the TIMP-2 and MMP-14 level. The survival in the MET group was significantly prolonged compared to the control and MTD groups. Long-term MET scheduling suppresses tumor growth and metastasis via its potent anti-angiogenic properties and a decrease in MMPs and TIMPs activities. These results provide a rationale for long-term MET dosing in future clinical trials of HCC treatment.     

Highly sensitive phototransistor with crystalline microribbons from new π-extended pyrene derivative via solution-phase self-assembly

A new pyrene-cored π-conjugated molecule has been synthesized through Sonogashira coupling reaction. The single-crystalline microribbon-based FET exhibited the highest mobility of 0.7 cm(2) V(-1) s(-1) (I(on)/I(off) > 10(6)). Single-crystalline microribbons were employed to operate in an organic phototransistor (OPT) under very low light intensity (I = 5.6 μW cm(-2)).