Electrical Characteristics and Reliability of Nitrogen-Stuffed Porous Low-k SiOCH/Mn2O3-xN/Cu Integration.

In our previous study, a novel barrier processing on a porous low-dielectric constant (low-k) film was developed: an ultrathin Mn oxide on a nitrogen-stuffed porous carbon-doped organosilica film (p-SiOCH(N)) as a barrier of the Cu film was fabricated. To form a better barrier Mn2O3-xN film, additional annealing at 450 °C was implemented. In this study, the electrical characteristics and reliability of this integrated Cu/Mn2O3-xN/p-SiOCH(N)/Si structure were investigated. The proposed Cu/Mn2O3-xN/p-SiOCH(N)/Si capacitors exhibited poor dielectric breakdown characteristics in the as-fabricated stage, although, less degradation was found after thermal stress. Moreover, its time-dependence-dielectric-breakdown electric-field acceleration factor slightly increased after thermal stress, leading to a larger dielectric lifetime in a low electric-field as compared to other metal-insulator-silicon (MIS) capacitors. Furthermore, its Cu barrier ability under electrical or thermal stress was improved. As a consequence, the proposed Cu/Mn2O3-xN/p-SiCOH(N) scheme is promising integrity for back-end-of-line interconnects.

Use of a fluorinated probe to quantitatively monitor amino acid binding preferences of ruthenium(ii) arene complexes.

In order to address outstanding questions about ruthenium complexes in complex biological solutions, 19F NMR spectroscopy was used to follow the binding preferences between fluorinated RuII(η6-arene)(bipyridine) complexes and protected amino acids and glutathione. Reporting what ruthenium compounds bind to in complex environments has so far been restricted to relatively qualitative methods, such as mass spectrometry and X-ray spectroscopic methods; however, quantitative information on the species present in the solution phase cannot be inferred from these techniques. Furthermore, using 1H NMR, in water, to distinguish and monitor a number of different complex RuII(η6-arene) adducts forming is challenging. Incorporating an NMR active heteroatom into ruthenium organometallic complexes provides a quantitative, diagnostic 'fingerprint' to track solution-phase behaviour and allow for unambiguous assignment of any given adduct. The resulting 19F NMR spectra show for the first time the varied, dynamic behaviour of organoruthenium compounds when exposed to simple biomolecules in complex mixtures. The rates of formation of the different observed species are dramatically influenced by the electronic properties at the metal, even in a closely related series of complexes in which only the electron-donating properties of the arene ligand are altered. Preference for cysteine binding is absolute: the first quantitative solution-phase evidence of such behaviour.

Invasive pattern grading score designed as an independent prognostic indicator in oral squamous cell carcinoma.

AIMS: To test the validity of an invasive pattern grading score (IPGS) developed for oral squamous cell carcinoma (OSCC) as a prognostic indicator and to elucidate the relationship between the IPGS and clinical parameters. METHODS AND RESULTS: The IPGS was applied to a total of 153 cases of OSCC. There were significant correlations between IPGS and distant metastasis (P = 0.01) or recurrence (P = 0.001). However, there were no significant correlations between IPGS and gender, age, size or extent, location, status of lymph node metastasis, clinical staging, or histological grading. Cases of OSCC with higher IPGS were associated with poor patient survival (P < 0.001) and higher probability of tumour recurrence (P = 0.001). Intraobserver (kappa = 0.74) and interobserver agreement (kappa = 0.67) were very satisfactory. CONCLUSIONS: Our study confirms the validity of the IPGS, an indicator that is simple and easy to use. IPGS not only provides histological assessment of biological behaviour, but also offers an independent prognostic factor that may influence the treatment of OSCC.

Effects of small interfering RNAs targeting Fascin on gene expression in oral cancer cells.

BACKGROUND: Oral squamous cell carcinoma (OSCC) is one of the most common head and neck cancers. The prognosis of OSCC is usually poor because of extensive local invasion at initial diagnosis. In the literature, Fascin has been reported responsible for cell motility and over-expression of Fascin contributes to an unfavorable clinical course. Nevertheless, the roles of Fascin protein playing in aggressiveness of OSCC and their potential mechanisms need to be elucidated. METHODS: Two cell lines of OSCC (OECM-1 and SCC-25) via the vector-based small interfering RNA (siRNA) to suppress the expression of the Fascin gene were used. Subsequent analyses and observation regarding the expression of Fascin protein and cyto-morphological alterations were detected by Western blot and immunofluorescent microscopy. Boyden chamber invasion assay, cell migration assay and adhesion assay were also applied to investigate the functional changes of OSCC. RESULTS: There were statistically significant differences (P < 0.05) of Fascin expression before and after silencing. Down-regulation of Fascin protein directly led to changes of cell surface protrusions under immunofluorescent microscopy and resulted in suppression of migration, invasion and increase of adhesion in both cell lines (P < 0.05). Furthermore, down-regulation of Fascin expression also resulted in alterations of E-cadherin, beta-catenin and TWIST at certain level, implicative of an association with epithelial-mesenchymal transition (EMT). CONCLUSIONS: Our results suggest that expression of Fascin protein may play an essential role in regulation of progression of OSCC and contributes to the event of EMT in the early aggressiveness of OSCC.

Molecular mass and antitumor activities of sulfated derivatives of alpha-glucan from Poria cocos mycelia.

Two kinds of water-insoluble (1-->3)-alpha-D-glucan samples, ab-PCM3-I and ac-PCM3-I, isolated from different Poria cocos mycelia were sulfated, to produce two series of water-soluble derivatives ab-PCM3-I-S1-S5 and ac-PCM3-I-S1-S5, respectively. The derivatives having different weight-average molecular mass (Mw) were produced by changing reaction temperature and time as well as molar ratios between chlorosulfonic acid and number of hydroxyl groups in the glucan. The degrees of substitution (DS) of the sulfated derivatives were analyzed by elemental analysis (EA) to be 0.39-0.67 for ab-PCM3-I-S and 0.73-0.96 for ac-PCM3-I-S, respectively. The Mw and the intrinsic viscosity ([eta]) of the samples ab-PCM3-I-S and the ac-PCM3-I-S were measured by size exclusion chromatography combined with laser light scattering (SEC-LLS) and viscometry in phosphate buffer solution (PBS) at 37 degrees C. The results indicated that their Mw ranged from 2.0 to 11.3 x 10(4) for the samples ab-PCM3-I-S, and 4.7 to 40.0 x 10(4) for the samples ac-PCM3-I-S. Moreover, the antitumor activities of the sulfated derivatives ab-PCM3-I-S and ac-PCM3-I-S against Sarcoma 180 tumor cell tested both in vitro and in vivo are significantly higher than those of the native alpha-D-glucans. Therefore, a moderate range of molecular mass from 2.0 x 10(4) to 40.0 x 10(4), relatively high chain stiffness and good water solubility of the sulfated derivatives are beneficial to the enhancement of their antitumor activities.

Antitumor activities of heteropolysaccharides of Poria cocos mycelia from different strains and culture media.

Ten water-soluble heteropolysaccharide fractions were isolated from Poria cocos mycelia cultured from one wild and one cultivated strain in two identical culture media differing only in one component: either corn steep liquor or bran extract. The chemical compositions, including monosaccharide profile, protein content, and molecular mass M(w) of the mycelial polysaccharides were determined. Both the in vitro and in vivo antitumor activities of the heteropolysaccharides were evaluated and compared. The heteropolysaccharides from Poria cocos mycelia cultured with the wild strain in a medium containing corn steep liquor exhibited the highest antitumor activities against Sarcoma 180 in vivo.