26 research outputs found

    Synthesis and Properties of Pyrrolidinium and Piperidinium Bis(trifluoromethanesulfonyl)imide Ionic Liquids with Allyl Substituents

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    New pyrrolidinium and piperidinium bis(trifluoromethanesulfonyl)imide (TFSI) ionic liquids (ILs) having allyl substituents were synthesized and characterized. All of them are liquid at room temperature and stable up to 300 oC. The pyrrolidinium-based ILs showed better conductivities and lower viscosities than the corresponding piperidinium-based ILs. Among them, 1-allyl-1-methylpyrrolidinium TFSI showed the lowest viscosity of 52 cP, the highest conductivity of 5.7 mS cmโˆ’1, and the most negative cathodic voltage window of โˆ’3.2 V (vs. Fc/Fc+) on a platinum electrode, which are the improved results compared to the corresponding analogue having a saturated substituent, 1-methyl-1-propylpyrrolidinium TFSI.This work was supported by the Division of Advanced Batteries in NGE Program (Project No. 10016439) and by KOSEF through the Research Center for Energy Conversion and Storage. We also thank BK 21 Project funded by the Ministry of Education and Human Resources Development of Korea

    Synthesis and Physicochemical Properties of Ionic Liquids: 1-Alkenyl-2,3-dimethylimidazolium Tetrafluoroborates

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    1-Alkenyl-2,3-dimethylimidazolium tetrafluoroborate ionic liquids having an olefinic substituent were synthesized and characterized. Among them, [AMMIm]BF4 with an allyl group showed lower viscosity, higher ionic conductivity, and a wider electrochemical window compared with its analogue having a saturated alkyl substituent. An EDLC with [AMMIm]BF4 showed better performance than that with [PMMIm]BF4, too.This work was supported by the Division of Advanced Batteries in NGE Program (Project No. 10016439) and by KOSEF through the Research Center for Energy Conversion and Storage. We also gratefully acknowledge the financial support by the BK 21 Project funded by the Ministry of Education and Human Resources Development of Korea

    Maternal, neonatal, and child health systems under rapid urbanization: a qualitative study in a suburban district in Vietnam

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    Background Vietnam has been successful in increasing access to maternal, neonatal, and child health (MNCH) services during last decades; however, little is known about whether the primary MNCH service utilization has been properly utilized under the recent rapid urbanization. We aimed to examine current MNCH service utilization patterns at a district level. Methods The study was conducted qualitatively in a rural district named Quแป‘c Oai. Women who gave a birth within a year and medical staff at various levels participated through 43 individual in-depth interviews and 3 focus group interviews. Results Primary MNCH services were underutilized due to a failure to meet increased quality needs. Most of the mothers preferred private clinics for antenatal care and the district hospital for delivery due to the better service quality of these facilities compared to that of the commune health stations (CHSs). Mothers had few sociocultural barriers to acquiring service information or utilizing services based on their improved standard of living. A financial burden for some services, including caesarian section, still existed for uninsured mothers, while their insured counterparts had relatively few difficulties. Conclusions For the improved macro-efficiency of MNCH systems, the government needs to rearrange human resources and/or merge some CHSs to achieve economies of scale and align with service volume distribution across the different levels.This research was financially supported by the JW LEE Center for Global Medicine of Seoul National University College of Medicine, Seoul, South Korea. Vietnam Health System Strengthening project is part of a collaborative project by and JW LEE Center for Global Medicine of Seoul National University College of Medicine, Seoul, South Korea and University of Hanoi, University of Medicine and Pharmacy of Ho Chi Minh City. The funding source had no role in study design, data collection and analysis, interpretation of data, or preparation of the manuscript

    cdc-25.4, a Caenorhabditis elegans Ortholog of cdc25, Is Required for Male Mating Behavior

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    Cell division cycle 25 (cdc25) is an evolutionarily conserved phosphatase that promotes cell cycle progression. Among the four cdc25 orthologs in Caenorhabditis elegans, we found that cdc-25.4 mutant males failed to produce outcrossed progeny. This was not caused by defects in sperm development, but by defects in male mating behavior. The cdc-25.4 mutant males showed various defects during male mating, including contact response, backing, turning, and vulva location. Aberrant turning behavior was the most prominent defect in the cdc-25.4 mutant males. We also found that cdc-25.4 is expressed in many neuronal cells throughout development. The turning defect in cdc-25.4 mutant males was recovered by cdc-25.4 transgenic expression in neuronal cells, suggesting that cdc-25.4 functions in neurons for male mating. However, the neuronal morphology of cdc-25.4 mutant males appeared to be normal, as examined with several neuronal markers. Also, RNAi depletion of wee-1.3, a C. elegans ortholog of Wee1/Myt1 kinase, failed to suppress the mating defects of cdc-25.4 mutant males. These findings suggest that, for successful male mating, cdc-25.4 does not target cell cycles that are required for neuronal differentiation and development. Rather, cdc-25.4 likely regulates noncanonical substrates in neuronal cells

    The Antitubercular Activities of Natural Products with Fused-Nitrogen-Containing Heterocycles

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    Tuberculosis (TB) is notorious as the leading cause of death worldwide due to a single infectious entity and its causative agent, Mycobacterium tuberculosis (Mtb), has been able to evolve resistance to all existing drugs in the treatment arsenal complicating disease management programs. In drug discovery efforts, natural products are important starting points in generating novel scaffolds that have evolved to specifically bind to vulnerable targets not only in pathogens such as Mtb, but also in mammalian targets associated with human diseases. Structural diversity is one of the most attractive features of natural products. This review provides a summary of fused-nitrogen-containing heterocycles found in the natural products reported in the literature that are known to have antitubercular activities. The structurally targeted natural products discussed in this review could provide a revealing insight into novel chemical aspects with novel biological functions for TB drug discovery efforts

    A Web Service Approach to Universal Accessibility

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    The enormous growth in wireless communications and miniaturized handheld devices in the last few years, have given rise to a vast range of new services, for heterogeneous user environments. In this paper, we investigate the nature of designing distributed services that accommodate pervasive devices. We introduce Universal Accessible Web service architecture, CAROUSEL Web service. We present our collaborative Web services model linked with an event brokering service, NaradaBrokering. We discuss how a rich synchronous and asynchronous collaboration environment can support virtual communications while being built on top of a Web service infrastructure, based on industry standard portal technologies such as XML, Apacheโ€™s Jetspeed, and WSDL. The linkage of the event brokering system with a Web service based architecture is one of the critical design issues in message-based collaborative application. We also describe the approach to universal access mechanisms in our collaborative Web service model. Also included is a discussion of the prototype collaborative SVG (Scalable Vector Graphics) browser that we developed as a Web service

    Universal Accessible Collaboration Frameworks for Ubiquitous Computing Environments

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    The advances in mobile devices, wireless communication, and messaging technologies have given rise to a vast range of new services, for heterogeneous user environments. These include a collaboration service that can be accessed regardless of the nature of user devices and physical capabilities of the user. In this paper, we present an overview of our research project CAROUSEL, universal accessible collaboration frameworks. We describe two collaborative frameworks; our initial approach using a special PDA adaptor and current investigation using Web Services model. Although the two systems are functionally similar, there are differences in the degree of interoperability, scalability and reusability of the infrastructure. In Web Services case, we discuss how a rich synchronous and asynchronous collaboration environment can support virtual communications while built on top of a Web service infrastructure. We also describe the approach to universal access mechanisms in our collaborative model.
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