The title salt,[K(2)(C(16)H(12)O(6))](n), was obtained by the reaction of 1,2-bis-[4-(ethyl-carbox-yl)-phenox-yl]ethane with KOH in water. The anion lies on a crystallographic inversion center, which is located at the mid-point of the central C-C bond. The K(+) cation is coordinated by six O atoms, two from the chelating carboxyl-ate group of the anion and four from four neighboring and monodentately binding anions, giving rise to an irregular [KO(6)] coordination polyhedron. The coordination mode of the cation leads to the formation of K/O layers parallel to (100). These layers are linked by the nearly coplanar anions (r.m.s. deviation of 0.064 Å of the carboxyl, aryl and O-CH(2) groups from the least-squares plane) into a three-dimentional network.

Conventional integral equation methods for diffraction gratings require lattice sum techniques to evaluate quasi-periodic Green's functions. The boundary integral equation Neumann-to-Dirichlet map (BIE-NtD) method in Wu and Lu [J. Opt. Soc. Am. A26, 2444 (2009)],[J. Opt. Soc. Am. A28, 1191 (2011)] is a recently developed integral equation method that avoids the quasi-periodic Green's functions and is relatively easy to implement. In this paper, we present a number of improvements for this method, including a revised formulation that is more stable numerically, and more accurate methods for computing tangential derivatives along material interfaces and for matching boundary conditions with the homogeneous top and bottom regions. Numerical examples indicate that the improved BIE-NtD map method achieves a high order of accuracy for in-plane and conical diffractions of dielectric gratings.

A methodology is described to objectively diagnose the quality of speech signals by predicting the perceptual detectability of a selected set of distortions. The distortions are a statistically selected subset of the broad number of distortions used in diagnostic acceptability measure (DAM) testing. The justification for such a methodology is established from the analysis of a set of speech signals representing a broad set of distortions and their respective DAM scores. At the heart of the ability to isolate and diagnose the perceptibility of the individual distortions is a physiologically motivated cochlear model. The philosophy and methodology is thus distinct from traditional objective measures that are typically designed to predict mean opinion scores (MOS) using well versed functional psychoacoustic models. Even so, a weighted sum of these objectively predicted set of distortions is able to predict accurate and robust MOS scores, even when the reference speech signals have been subject to the Lombard effect.

Image denoising and signal enhancement are two common steps to improve particle contrast for detection in low signal-to-noise ratio (SNR) fluorescence live-cell images. However, denoising may oversmooth features of interest, particularly weak features, leading to false negative detection. Here we propose a robust framework for particle detection in which image denoising in the grayscale image is not needed, so avoiding image oversmoothing. A key to our approach is the new development of a particle enhancement filter based on the recently proposed particle probability image to obtain significantly enhanced particle features and greatly suppressed background in low SNR and low contrast environments. The new detection method is formed by combining foreground and background markers with watershed transform operating in both particle probability and grayscale spaces; dynamical switchings between the two spaces can optimally make use the information in images for accurate determination of particle position, size and intensity. We further develop the interacting multiple mode filter for particle motion modeling and data association by incorporating the extra information obtained from our particle detector to enhance the efficiency of multiple particle tracking. We find that our methods lead to significant improvements in particle detection and tracking efficiency in fluorescence live-cell applications.

Durability is an important issue in proton-exchange membrane fuel cells (PEMFCs). One of the major challenges lies in the degradation caused by the oxidation of the carbon support under high anode potentials (under fuel starvation conditions). Herein, we report highly stable, carbon-free, WO(3) nanoclusters as catalyst supports. The WO(3) nanoclusters are synthesized through a hard template method and characterized by means of electron microscopy and electrochemical analysis. The electrochemical studies show that the WO(3) nanoclusters have excellent electrochemical stability under a high potential (1.6 V for 10 h) compared to Vulcan XC-72. Pt nanoparticles supported on these nanoclusters exhibit high and stable electrocatalytic activity for the oxidation of hydrogen. The catalyst shows negligible loss in electrochemically active surface area (ECA) after an accelerated durability test, whereas the ECA of the Pt nanoparticles immobilized on conventional carbon decreases significantly after the same oxidation condition. Therefore, Pt/WO(3) could be considered as a promising alternative anode catalyst for PEMFCs.

Herein, poly[2,2'-(p-oxydiphenylene)-5,5'-benzimidazole](PBI) is synthesized from 3,3'-diaminobenzidine and 4,4'-oxybisbenzoic acid, and the membrane is prepared by solvent casting. The main characteristics of PBI are studied. In the preparation of the PBI/H(3) PO(4) composite membrane, the absorbing temperature of H(3) PO(4) is 120 °C, which leads to a membrane with a high content of H(3) PO(4). Membrane electrode assemblies (MEAs) are fabricated from PBI/H(3) PO(4) membranes with the catalyst layer made of Pt/C, PBI, and polyvinylidene fluoride (230:12:7 w/w). The fabricated MEA is tested at 150 °C with dry hydrogen and oxygen gas at 0.2 MPa for both anode and cathode feeds. No degradation of voltage is seen during stability testing of the PBI/H(3) PO(4) membrane at a constant current for 100 h. The maximum power density is 1.17 W cm(-2), and the maximum current density is 6.0 A cm(-2) with a Pt loading of 0.5 mg cm(-2). The high performance of these membrane materials demonstrates that PBI can be regarded as an alternative membrane material for high-temperature proton-exchange-membrane fuel cells.

MicroRNAs (miRNAs) act as important gene regulators in human genomes and their aberrant expression links to many malignancies. We previously identified a different characteristic miRNA expression profile in cervical cancer from that in cervical normal tissues, including the downregulated miR-424. However, the role and mechanism of miR-424 in cervical cancer still remain unknown. Here, we focused on identifying the tumor-suppressive function and clinical significance of miR-424 and exploring the mechanistic relevance by characterizing its target. We showed a significantly decreased expression of miR-424 in 147 cervical cancer tissues versus 74 cervical normal tissues by performing quantitative RT-PCR. In 147 cervical cancer tissue samples, low-level expression of miR-424 was positively correlated with poor tumor differentiation, advanced clinical stage, lymph node metastasis and other poor prognostic clinicopathological parameters. Further in vitro observations showed that enforced expression of miR-424 inhibited cell growth by both enhancing apoptosis and blocking G1/S transition, and suppressed cell migration and invasion in two human cervical cancer cell lines, SiHa and CaSki, implying that miR-424 functions as a tumor suppressor in the progression of cervical cancer. Interestingly, overexpression of miR-424 inhibited the expression of protein checkpoint kinase 1 (Chk1) and phosphorylated Chk1 (p-Chk1) at residues Ser345 and decreased the activity of luciferase-reporter containing the 3'-untranslated region (UTR) of Chk1 with predicted miR-424-binding site. Moreover, miR-424 expression levels were inversely correlated with Chk1 and p-Chk1 protein levels in both cervical cancer and normal tissues. Furthermore, RNAi-mediated knockdown of Chk1 decreased matrix metalloproteinase 9 expression and phenocopied the tumor suppressive effects of miR-424 in cell models. Taken together, our results identify a crucial tumor suppressive role of miR-424 in the progression of cervical cancer at least partly via upreglating the expression of Chk1 and p-Chk1, and suggest that miR-424 might be a candidate of prognostic predictor or an anticancer therapeutic target for cervical cancer patients.Oncogene advance online publication, 2 April 2012; doi:10.1038/onc.2012.121.

OBJECTIVE To investigate clinical outcomes and fertility status of conservative treatment for epithelial ovarian carcinoma. METHODS The data of clinicopathological characteristics and follow-up were retrospectively collected and analyzed in 17 patients with early epithelial ovarian carcinoma who underwent conservative surgery. RESULTS The tumor histologic types of 17 patients included 13 mucinous, one serous, one endometrioid, and two mixed mucinous and serous carcinomas. The FIGO stages were: ten Stage IA, six IC, and one IIIA disease. Tumor grades involved 15 grade 1 and two grade 2. Sixteen patients received adjuvant platinum-based combined chemotherapy. The medium duration of follow-up was 61 months (range 17-115 months). Only one patient recurred at 36 months after primary surgery. All of the 17 patients were alive at end of follow-up. Eight patients attempted pregnancy and five patients conceived naturally; there were six term pregnancies and one abortion. CONCLUSION Conservative surgery can be considered for young patients with FIGO Stage I including grade 1 and grade 2 epithelial ovarian cancers who desire further childbearing.

The so-called receiver operating characteristic technique is used as a tool in an optimization procedure for the improvement and assessment of a filter-based methodology for the location of hot spots in protein sequences and exons in DNA sequences. By optimizing the characteristic values of the nucleotides, high efficiency as well as improved accuracy can be achieved relative to results obtained with the electron-ion interaction potentials. On the other hand, by using the proposed filterbased methodology with binary sequences, improved accuracy can be achieved although the efficiency is somewhat compromised relative to that achieved using the optimized characteristic values. Extensive experimental results, evaluated using measures such as the g-mean, the Matthews correlation coefficient, and the chisquare statistic, show that the filter-based methodology performs much better than existing techniques using the short-time discrete Fourier transform, particularly in applications where short exons are involved.

Ion beam transport from the Superconducting Electron Cyclotron Resonance ion source with Advanced design in Lanzhou (SECRAL) electron cyclotron resonance ion source was studied at the Institute of Modern Physics during 2010. Particle-in-cell simulations and experimental results have shown that both space charge and magnetic aberrations lead to a larger beam envelope and emittance growth. In the existing SECRAL extraction beam line, it has been shown that raising the solenoid lens magnetic field reduces aberrations in the subsequent dipole and results in lower emittance. Detailed beam emittance measurements are presented in this paper.