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A visible light-induced process for selective difluoroalkylation of unactivated alkenes has been developed. The choice of base is crucial for governing the chemoselectivity of the process to produce difluoroalkylated alkanes and alkenes. [ABSTRACT FROM AUTHOR]

Pyruvate is an endogenous antioxidant and anti-inflammatory substance. The present study was implemented to investigate the protective effect of ethyl pyruvate (EP) against the development and progression of diabetic nephropathy in an in vivo and in vitro model. Diabetic rats were prepared by injecting streptozotocin (65 mg/kg). Those that developed diabetes after 72 h were treated with EP (40 mg/kg) intraperitoneally. Diabetic rats without pyruvate treatment and nondiabetic rats were used for control. As an in vitro experiment, rat mesangial cells cultured primarily from Sprague-Dawley rats were treated in high-glucose (HG, 50 mM) or normal-glucose (NG, 5 mM) conditions and with or without pyruvate. Pyruvate-treated diabetic rats exhibited decreased albuminuria and attenuated NADPH-dependent reactive oxygen species generation. Immunohistochemistry showed reduced laminin, type IV collagen, and fibronectin deposition in the glomeruli compared with nontreated diabetic rats. Parallel changes were shown in tissue mRNA and protein expression levels of monocyte chemoattractant protein-1, transforming growth factor-β1, laminin, fibronectin, and type IV collagen in the kidney. Concordantly, protective effects were also exhibited in the mesangial cell culture system. These findings suggest that pyruvate protects against kidney injury via NADPH oxidase inhibition. The present study established that activation of NADPH oxidase plays a crucial role in diabetes-induced oxidative stress, glomerular hypertrophy, and ECM molecule expression. Pyruvate exhibited a renoprotective effect in the progression of experimental diabetic nephropathy. Future research is warranted to investigate the protective mechanism of pyruvate more specifically in relation to NADPH oxidase in diabetic nephropathy. [ABSTRACT FROM AUTHOR]

This paper evaluates the efficiency of mobile content firms through a hybrid approach combining data envelopment analysis (DEA) to analyze the relative efficiency and performance of firms and principal component analysis (PCA) to analyze data structures. We performed a DEA using the total amount of assets, operating costs, employees, and years in business as inputs, and revenue as output. We calculated fifteen combinations of DEA efficiency in the mobile content firms. We performed a PCA on the results of the fifteen DEA models, dividing the mobile content firms intothose having either ‘asset-oriented’ or ‘manpower and experience-oriented’ efficiency. Discriminant analysis was used to validate the relationship between the efficiency models and mobile content types. This paper contributes toward the construction of a framework that combines the DEA and PCA approaches in mobile content firms for use in comprehensive measurements. Such a framework has the potential to present major factors of efficiency for sustainable management in mobile content firms and to aid in planning mobile content industry policies. [ABSTRACT FROM AUTHOR]

Infection with the human pathogen Vibrio vulnificus leads to the generation of reactive oxygen species (ROS) via NAD(P)H oxidase (Nox) in host cells. In the present study, we employed mutant V. vulnificus strains to identify an essential virulence factor responsible for this ROS generation. We found that repeats-in-toxin A1 (RtxA1) expressed by V. vulnificus acts via Nox1 to induce significant ROS generation in the intestine epithelial cells, which ultimately results in cell death. Furthermore, RtxA1 modulates the small GTPase Rac2, which is known to play an important role in the activation of Nox. When mice were infected by the oral method, in contrast with the wild-type bacteria, an RtxA1-deficient V. vulnificus mutant was unable to induce ROS generation within the intestine and failed to cause death. These findings strongly suggest that RtxA1-induced Rac2 expression is a critical step underlying the pathogenicity of V. vulnificus. [ABSTRACT FROM AUTHOR]

Anthraquinone-based fluorescent receptor 1 was immobilized on mesoporous silica (AFMS) or on silica particles (AFSP) via a sol–gel reaction. The sensing abilities of AFMS and AFSP were studied by addition of the anions F−, Cl−, Br−, I− and HSO4− to water suspensions of the assayed solid. The addition of fluoride ions to a suspension of AFMS resulted in a large decrease in the fluorescence intensity of the anthraquinone of AFMS. Thus, fluoride ions bind to two urea N–H protons of receptor 1 in AFMS. In contrast, the addition of Cl−, Br−, I− or HSO4− did not reduce the fluorescence of AFMS. In the case of AFSP, the sensitivity for fluoride ions was 10 times lower than that of AFMS due to the immobilization of smaller amounts of receptor 1 on the silica particles. A linear response of AFMS upon the addition of fluoride ions was observed between 0.50 μM and 10.0 μM, with a detection limit of ∼0.50 μM. These results suggest that mesoporous silica with its large surface area is useful as a supporting material. Furthermore, receptor 1 was also immobilized on a glass slide surface by a sol–gel reaction. The fluorescence of 1 immobilized on a glass slide was quenched when dipped into F− solution. On the other hand, no fluorescence change was observed in Cl− solution. These results imply that 1 immobilized on a glass slide is applicable as a portable fluorescent sensor for detection of fluoride ions in the biological and environmental fields. [ABSTRACT FROM AUTHOR]

We synthesized a tetrameric amphiphilic molecule ( 1) based on a calix[4]arene building block that self-assembled into different tunable and stable aggregation structures at different pH values in aqueous solution. The amphiphilic calix[4]arene molecule ( 1) formed a spherical structure at pH 3. However, 1formed a hollow necklacelike structure of 500 nm diameter at pH 7. These results indicate that the self-assembled morphologies of 1are strongly dependent on pH values. In addition, a 3D dendritic silver nanostructure was obtained by the self-assembly of 1at pH 7. [ABSTRACT FROM AUTHOR]

Abstract??Current progress integrating stem cell biology and tissue engineering techniques has been invaluable to clinical applications. Prior to the application of celluar transplantation technique to patients, we need to establish techniques that can monitor their tissue biodistribution non-invasively. In this study, we proposed an imaging modality using MRI to not only monitor implanted scaffoldin vivo, but also to track transplanted cells and behavior around the implant. For this purpose, human bone marrow-derived mesenchymal stem cells (hMSCs) were labeled with superparamagnetic iron oxide (Feridex) and then labeled hMSCs were cultured in a gelatin sponge used as a scaffold to support cell growth and proliferation. Histological assessment and MTT assay showed that cell labeling with MR contrast agent did not harm cell viability. Also, Feridex-labeled hMSCs showed a significant decrease in T2 signal intensity, even within the gelatin spongein vitro. After implanting the sponge/cell complexin vivo, we could visualize cellular behavior around the implant over time using a noninvasive MRI modality and this finding was correlated with histological study, which illustrates the potential of a new approach proposed here forin vivomonitoring of implanted cell-based tissue-engineered product. [ABSTRACT FROM AUTHOR]

The trifluoromethyl group can dramatically influence the properties of organic molecules, thereby increasing their applicability as Pharmaceuticals, agrochemicats, or building blocks for organic materials. Despite the importance of this substituent, no general method exists for its installment onto functionalized aromatic substrates. Current methods either require the use of harsh reaction conditions or suffer from a limited substrate scope. Here we report the palladium-catalyzed trifluoromethylation of aryl chlorides under mild conditions, allowing the transformation of a wide range of substrates, including heterocycles, in excellent yields. The process tolerates functional groups such as esters, amides, ethers, acetals, nitrites, and tertiary amines and, therefore, should be applicable to (ate-stage modifications of advanced intermediates. We have also prepared all the putative intermediates in the catalytic cycle and demonstrated their viability in the process. [ABSTRACT FROM AUTHOR]

A terpyridine-based organic−inorganic hybrid molecule was synthesized, and its self-assembled nanostructure with palladium was characterized. The catalyst activity of the nanofibers was examined in the Sonogashira coupling and the Heck reactions at reflux temperature. [ABSTRACT FROM AUTHOR]

Enyne metathesis is unique for its capacity to carry out multiple bond formation in tandem fashion. Its combined use with metallotropic 1,3-shift allowed for the development of a novel strategy for the total synthesis of a conjugated 1,3-diyne-containing natural product (3R,9R,10R)-panaxytriol. [ABSTRACT FROM AUTHOR]

The article describes the highly regioselective Alder ene reaction of 1,3-diynes and 1,3,5-triynes using ruthenium catalysts. The regioselectivity profile was evaluated using symmetrical 1,3-diynes to avoid any potential site-selectivity problem. It indicates that one of the alkynyl moieties of 1,3-diynes not participating in the reaction determines the regiochemistry, while the interplay between steric hindrance and polar substituents at the propargylic sites determines the site-selectivity.

SCH 351448 is a novel activator of low-density lipoprotein receptor promoter, which was discovered from the organic extract of the fermentation broth of a Micromonospora microorganism. The structure of SCH 351448 features a 28-membered macrodiolide consisting of two identical hydroxy carboxylic acid units. Authors report the first total synthesis of this molecule. Synthetic plan called for double combination of units A and B, and the olefin metathesis reaction was envisaged for macrodiolide synthesis.

Provides information about supramolecules. Properties of supramolecules; Significance of fluorescence for chemical trace detection.

Polyphenols have been reported to possess anti-inflammatory activity, thereby act as chemopreventive agents. The objective of this study was to evaluate quercetin and keampferol as anti-inflammatory agents, and to assess their effects on colon cancer cell growth and angiogenic factor production. Human colon cancer cells (HT-29) were treated with 20 and 50 µM of quercetin or kaempferol for 24 to 72 hrs. The level of NO and PGE2 in culture media were measured as inflammatory markers for inflammatory responses. Cell proliferation, MMP activity and VEGF secretion were measured. Results showed that quercetin and kaempferol at 20-50µM reduced NO production, while PGE2 secretion was suppressed only by kaempferol. Both flavonoids inhibited cell proliferation in a dose-dependent manner. No synergistic effect on cell growth in inhibition was observed in 1:1 combination treatment. Kaempferol at 25 µM significantly decreased MMP-2 activity and VEGF production. These results suggest that quercetin and kaempferol possess cancer cell growth inhibitory effects. Keampferol exhibited superior anti-inflammatory activity, thereby significantly reduce angiogenic factor production. [ABSTRACT FROM AUTHOR]

The rod-like silica structure was obtained by inner sol--gel polymerization of BTEB using the organic tube 1 as a template, and its gas-absorption property was characterized. The organic silica rod-like material absorbed 0.68 wt % of hydrogen at 78 K. [ABSTRACT FROM AUTHOR]

Halogenated organic compounds are important anthropogenic chemicals widely used in chemical industry, biology, and pharmacology; however, the persistence and inertness of organic halides cause human health problems and considerable environmental pollution. Thus, the elimination or replacement of halogen atoms with organic halides has been considered a central task in synthetic chemistry. In dehalogenation reactions, the consecutive single-electron transfer from reducing agents generates the radical and corresponding carbanion and thus removes the halogen atom as the leaving group. Herein, we report a new strategy for an efficient chemoselective hydrodehalogenation through the formation of stable carbanion intermediates, which are simply achieved by using highly mobile two-dimensional electrons of inorganic electride [Ca2N]+ ⋅ e- with effective electron transfer ability. The consecutive single-electron transfer from inorganic electride [Ca2N]+ ⋅ e- stabilized free carbanions, which is a key step in achieving the selective reaction. Furthermore, a determinant more important than leaving group ability is the stability control of free carbanions according to the s character determined by the backbone structure. We anticipate that this approach may provide new insight into selective chemical formation, including hydrodehalogenation. [ABSTRACT FROM AUTHOR]

Ornithine decarboxylase (ODC) is a rate-limiting enzyme in the first step of polyamine biosynthesis that is associated with cell growth and tumor formation. Existing catalytic inhibitors of ODC have lacked efficacy in clinical testing or displayed unacceptable toxicity. In this study, we report the identification of an effective and nontoxic allosteric inhibitor of ODC. Using computer docking simulation and an in vitro ODC enzyme assay, we identified herbacetin, a natural compound found in flax and other plants, as a novel ODC inhibitor. Mechanistic investigations defined aspartate 44 in ODC as critical for binding. Herbacetin exhibited potent anticancer activity in colon cancer cell lines expressing high levels of ODC. Intraperitoneal or oral administration of herbacetin effectively suppressed HCT116 xenograft tumor growth and also reduced the number and size of polyps in a mouse model of APC-driven colon cancer (ApcMin/+). Unlike the well-established ODC inhibitor DFMO, herbacetin treatment was not associated with hearing loss. Taken together, our findings defined the natural product herbacetin as an allosteric inhibitor of ODC with chemopreventive and antitumor activity in preclinical models of colon cancer, prompting its further investigation in clinical trials. [ABSTRACT FROM AUTHOR]

RSK2 is a widely expressed serine/threonine kinase, and its activation enhances cell proliferation. Here, we report that ATF1 is a novel substrate of RSK2 and that RSK2-ATF1 signaling plays an important role in EGF-induced neoplastic cell transformation. RSK2 phosphorylated ATF1 at Ser-63 and enhanced ATF1 transcriptional activity. Docking experiments using the crystal structure of the RSK2 N-terminal kinase domain combined with in vitro pulldown assays demonstrated that eriodictyol, a flavanone found in fruits, bound with the N-terminal kinase domain of RSK2 to inhibit RSK2 N-terminal kinase activity. In cells, eriodictyol inhibited phosphorylation of ATF1 but had no effect on the phosphorylation of RSK, MEK1/2, ERK1/2, p38 or JNKs, indicating that eriodictyol specifically suppresses RSK2 signaling. Furthermore, eriodictyol inhibited RSK2-mediated ATF1 transactivation and tumor promoter-induced transformation of JB6 Cl41 cells. Eriodictyol or knockdown of RSK2 or ATF1 also suppressed Ras-mediated focus formation. Overall, these results indicate that RSK2-ATF1 signaling plays an important role in neoplastic cell transformation and that eriodictyol is a novel natural compound for suppressing RSK2 kinase activity. [ABSTRACT FROM AUTHOR]

Abstract: Thermal, structural and optical properties of Nd3+ ions in tellurite glass (TeO2–ZnO–Na2O–Li2O–Nb2O5) have been investigated. Differential thermal analysis revealed reasonably good forming tendency of the glass composition. FTIR spectra were used to analyze the functional groups present in the glass. Judd–Ofelt intensity parameters were derived from the absorption spectrum and used to calculate the radiative lifetime, branching ratio and stimulated emission cross-section of the 4F3/2→4I9/2, 11/2, 13/2 transitions. The quantum efficiency of the 4F3/2 level is comparable as well as higher than the typical value of the other tellurite based glasses. The decay from the 4F3/2 level is found to be single exponential for different concentrations of Nd3+ ions with a shortening of lifetime with increasing concentration. The experimental values of branching ratio and saturation intensity of 4F3/2→4I11/2 transition indicate the favourable lasing action with low threshold power. [Copyright &y& Elsevier]