Legendrian singular links and singular connected sums

We study Legendrian singular links up to contact isotopy. Using a special property of the singular points, we define the singular connected sum of Legendrian singular links. This concept is a generalization of the connected sum and can be interpreted as a tangle replacement, which provides a way to classify Legendrian singular links. Moreover, we investigate several phenomena only occur in the Legendrian setup

Transparent conductive oxide films mixed with gallium oxide nanoparticle/single-walled carbon nanotube layer for deep ultraviolet light-emitting diodes

We propose a transparent conductive oxide electrode scheme of gallium oxide nanoparticle mixed with a single-walled carbon nanotube (Ga(2)O(3) NP/SWNT) layer for deep ultraviolet light-emitting diodes using spin and dipping methods. We investigated the electrical, optical and morphological properties of the Ga(2)O(3) NP/SWNT layers by increasing the thickness of SWNTs via multiple dipping processes. Compared with the undoped Ga(2)O(3) films (current level 9.9 × 10(-9) A @ 1 V, transmittance 68% @ 280 nm), the current level flowing in the Ga(2)O(3) NP/SWNT increased by approximately 4 × 10(5) times and the transmittance improved by 9% after 15 times dip-coating (current level 4 × 10(-4) A at 1 V; transmittance 77.0% at 280 nm). These improvements result from both native high transparency of Ga(2)O(3) NPs and high conductivity and effective current spreading of SWNTs

A Green Flag over Mobile Industry Start-Ups: Human Capital and Past Investors as Investment Signals

Crowdfunding and online start-up platforms are becoming important communication tools for start-ups and investors. Existing literatures on online start-up platforms usually focus on reward-based crowdfunding platform, which do not offer any equity to backers. In addition, there have not been many empirical researches about equity-based crowdfunding due to the novelty of the regulation. This study analyzes the association between funding amount and early stage start-ups’ underlying characteristics, the type of past investors, and influence of investors in the context of equity-based crowdfunding. The distinction of our research is the aspect of approach that we use population data from online start-up platform for the mobile industry. We find that start-up’s funding outcome is positively related to start-up’s human capital and pure investors. Moreover, our study extends theoretical understanding of the importance of human capital and past investors in start-up, and also contributes to the entrepreneurship literature by examining creditable signals for early stage start-up investment

Molecular mechanisms of heptaplatin effective against cisplatin-resistant cancer cell lines: less involvement of metallothionein

BACKGROUND: Heptaplatin is a new platinum derivative with anticancer activity against various cancer cell lines, including cisplatin-resistant cancer cell lines (Cancer Chemother Pharmacol 1995; 35: 441). METHODS: Molecular mechanisms of heptaplatin effective against cisplatin-resistant cancer cell lines has been investigated in connection with metallothionein (MT). Cytotoxicity was determined by an MTT assay. MT mRNA, was determined by RT-PCR assay. Transfection study was carried out to examine the function of MT. RESULTS: Of various gastric cancer cell lines, SNU-638 and SNU-601 showed the highest and lowest levels of MT mRNA, respectively, showing 80-fold difference. The IC(50 )values of SNU-638 to cisplatin, carboplatin and heptaplatin were 11.2-fold, 5.1-fold and 2.0-fold greater than those of SNU-601, respectively. Heptaplatin was more effective against cisplatin-resistant and MT-transfected gastric cancer sublines than cisplatin or carboplatin was. In addition, heptaplatin attenuated cadmium, but not zinc, induction of MT. CONCLUSION: These results indicate that molecular mechanisms of heptaplatin effective against cisplatin-resistant gastric cancer sublines is at least in part due to the less involvement of MT in heptaplatin resistance as well as its attenuation of MT induction

Modular evolution of glutathione peroxidase genes in association with different biochemical properties of their encoded proteins in invertebrate animals

<p>Abstract</p> <p>Background</p> <p>Phospholipid hydroperoxide glutathione peroxidases (PHGPx), the most abundant isoforms of GPx families, interfere directly with hydroperoxidation of lipids. Biochemical properties of these proteins vary along with their donor organisms, which has complicated the phylogenetic classification of diverse PHGPx-like proteins. Despite efforts for comprehensive analyses, the evolutionary aspects of GPx genes in invertebrates remain largely unknown.</p> <p>Results</p> <p>We isolated GPx homologs via <it>in silico </it>screening of genomic and/or expressed sequence tag databases of eukaryotic organisms including protostomian species. Genes showing strong similarity to the mammalian PHGPx genes were commonly found in all genomes examined. GPx3- and GPx7-like genes were additionally detected from nematodes and platyhelminths, respectively. The overall distribution of the PHGPx-like proteins with different biochemical properties was biased across taxa; selenium- and glutathione (GSH)-dependent proteins were exclusively detected in platyhelminth and deuterostomian species, whereas selenium-independent and thioredoxin (Trx)-dependent enzymes were isolated in the other taxa. In comparison of genomic organization, the GSH-dependent PHGPx genes showed a conserved architectural pattern, while their Trx-dependent counterparts displayed complex exon-intron structures. A codon for the resolving Cys engaged in reductant binding was found to be substituted in a series of genes. Selection pressure to maintain the selenocysteine codon in GSH-dependent genes also appeared to be relaxed during their evolution. With the dichotomized fashion in genomic organizations, a highly polytomic topology of their phylogenetic trees implied that the GPx genes have multiple evolutionary intermediate forms.</p> <p>Conclusion</p> <p>Comparative analysis of invertebrate GPx genes provides informative evidence to support the modular pathways of GPx evolution, which have been accompanied with sporadic expansion/deletion and exon-intron remodeling. The differentiated enzymatic properties might be acquired by the evolutionary relaxation of selection pressure and/or biochemical adaptation to the acting environments. Our present study would be beneficial to get detailed insights into the complex GPx evolution, and to understand the molecular basis of the specialized physiological implications of this antioxidant system in their respective donor organisms.</p

Incidentally Detected Situs Ambiguous in Adults

Situs ambiguous is rare congenital anomaly in adults. In 2 adult patients who admitted for different cardiac problems, situs ambiguous with polysplenia was detected. A 42-year-old male admitted for radio frequent catheter ablation of atrial fibrillation, and he had left-sided inferior vena cava (IVC), hepatic segment of IVC interruption with hemiazygos continuation, multiple spleens and intestinal malrotation. And in a 52-year-old female case who was hospitalized due to infective endocarditis after implanting pacemaker for sick sinus syndrome, multiple spleens, left-sided stomach, bilateral liver with midline gallbladder, and left-sided IVC were found. Those findings were consistent with situs ambiguous with polysplenia, but their features were distinctive