651 research outputs found

    An integrated damping and strengthening strategy for performance-based seismic design and retrofit of highway bridges

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    In this study, a damping-enhanced strengthening (DES) strategy was introduced to retrofit bridge structures for multiple performance objectives. The main objectives of this study are (1) to numerically demonstrate the effectiveness of the anchoring mechanism of a constrained damping layer in the proposed DES system, and (2) to evaluate the performances of a highway bridge retrofitted with a DES retrofit technique of viscoelastic (VE) damping and carbon-fiber-reinforced-polymer (CFRP) strengthening components that are nearly independent under weak earthquakes but strongly coupled under strong earthquakes --Abstract, page v

    The Role of Proteome in Cellular Zn2+ Trafficking and in the Ability of the Fluorescent Zinc Sensors to Image Intracellular Zn2+

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    Zinc is an essential biological trace metal used in as many as 3000 Zn-proteins, about 10% of the eukaryotic proteome, as either a structural constituent or a catalytic cofactor. These proteins include the zinc fingers, the most prevalent transcription factors that bind a wide range of gene promoters and thus regulate gene expression. A eukaryotic cell contains several hundred micromolar of Zn2+- almost all of it is bound to specific Zn-proteins. Recently, Zn2+ has been reported to serve as a regulatory signal and a neurotransmitter, suggesting that there also exists a dynamic Zn2+ pool in cells. These findings led to the synthesis of a wide range of fluorescent sensors to image intracellular mobile Zn2+. Despite extensive knowledge about thousands of Zn-proteins, the Zn2+ trafficking pathway from its entry into the cytosol by transporters to the formation of Zn-proteins is not well understood. This present work has studied the role of proteome in cellular Zn2+ trafficking using fluorescent zinc sensors, including FluoZin-3, Zinquin (ZQ), TSQ, Newport Green (NPG) and Zinpyr-1 (ZP1). The titration of proteome pre-treated with FluoZin-3, a relatively high affinity Zn2+ sensor with the stability constant of 15 nM, with Zn2+ has revealed that proteome contains a significant number of high affinity, non-specific Zn2+ binding sites, with the stability constants on the order of 10-10 M. The discovery of these high affinity binding sites of proteome suggested that along with Zn-metallothionein, proteome too can serve as a possible intermediate along the way to the formation of native Zn-proteins. Moreover, this finding raises the question how the majority of the fluorescent zinc sensors with the stability constants ranging from micromolar to nanomolar image intracellular labile Zn2+ by circumventing the proteome’s high zinc buffering capacity. Interestingly, the thiol binding reagents, N-ethylmaleimide (NEM) and DTNB abolished these high affinity sites, revealing the involvement of proteomic sulfhydryl groups in these Zn2+ binding sites. The loss of proteome’s zinc buffering capacity upon sulfhydryl modification can explain how the sensors bind the dynamic Zn2+ pool by surpassing the proteome’s high Zn2+ binding affinity. For example, Zinquin, a high affinity sensor with Kd of 2 nM, could bind the mobile Zn2+ only when the proteome was significantly modified by the reaction under investigation, such as the liberation of proteomic Zn2+ by nitric oxide, which reacts with the sulfhydryl groups and thus reduces proteome’s buffering capacity. In case of unperturbed proteome, these sensors either are unable to compete for mobile Zn2+ with proteome’s high affinity Zn2+ binding sites or generate ternary adduct, Proteome•Zn-Sensor, with Zn2+ preferentially bound to proteome. Newport Green, for example, with its modest stability constant (Kd 10-5 – 10-6 M) cannot efficiently compete with proteomic ligands to image mobile Zn2+. It could not bind intracellular Zn2+ shuttled into LLC-PK1 cells using the ionophore, pyrithione. Moreover, when proteomic Zn2+ was liberated by the reaction with sulfhydryl binding reagents, NEM and diethylamine NONOate (DEA-NO), in the presence of Newport Green, insignificant amount of Zn-NPG was detected. By contrast, the higher affinity Zn2+ sensor (Kd 0.7 nM) than Newport Green, ZP1 formed ternary adduct Proteome•Zn-ZP1 with the dynamic Zn2+, where Zn2+ is adventitiously bound to proteome’s high affinity zinc binding sites. Besides with the mobile Zn2+, ZP1 also seems to react with the static distribution of cellular Zn2+ in specific Zn-proteins and generates ZP1-Zn-Proteome ternary adduct. Therefore, the effectiveness of the sensors to bind the cellular dynamic Zn2+ is a variable of proteome’s Zn2+ binding characteristics

    Synthesis and Characterizations of Poly(3-hexylthiophene) and Modified Carbon Nanotube Composites

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    Poly(3-hexylthiophene) and modified (functionalized and silanized) multiwall carbon nanotube (MWNT) nanocomposites have been prepared through in situ polymerization process in chloroform medium with FeCl3 oxidant at room temperature. The composites are characterized through Fourier transfer infrared spectroscopy (FT-IR), Raman, and X-ray diffraction (XRD) measurements to probe the nature of interaction between the moieties. Optical properties of the composites are measured from ultraviolet-visible (UV-Vis) and photoluminescence (PL) spectroscopy. Conductivity of the composites is followed by four probe techniques to understand the conduction mechanism. The change (if any) in C=C symmetric and antisymmetric stretching frequencies in FT-IR, the shift in G band frequencies in Raman, any alterations in λmax of UV-Vis, and PL spectroscopic measurements are monitored with modified MWNT loading in the polymer matrix

    Adequate Antenatal Care Visits among Tribal Women in Bangladesh

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    Maternal mortality is a global concern, and peaks in developing countries. Adequate antenatal care services (ANCs) are indispensable for both maternal and fetal survival. A global trend leads us to the notion that aboriginal women are somewhat less privileged than non-tribal mothers around the world. Hence, this study determines the association of socio-economic status and adequate use of ANC facilities by Bangladesh's tribal women. This study is a quantitative study using a convenient sampling technique. Semi-structured questionnaires were used to obtain data on married women (n=556) between the ages of 15–49 who had children aged 1 year or under. The data were analyzed using the SPSS program (version 20). Associations were determined using Chi-square test and regression analysis of maternal health care services and the adequacy of ANC use. Significance was determined at p-value <0.10. Results show that only 29.9% of pregnant tribal women sought ANC services, of which 13.5% visits hospital for ANC services four times or more during pregnancy. Significant association between age at first marriage, religion, family planning with adequate use of ANC services was observed. This study concludes that women’s education, occupation, state of the economy, residence location, and distance from health care facilities all positively influences the adequate use of ANC services. Thus, upgrading socioeconomic status, decentralization of health facilities and women’s education is recommended for adequate utilization of ANC services

    INFLUENCE OF ABSURD THEATRICAL TRADITION IN MODERN ASSAMESE DRAMA: A COMPARATIVE STUDY WITH REFERENCE TO THE PLAYS OF ARUN SHARMA

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    The contemporary Assamese plays have developed as a result of numerous interwoven influences and channels. And it is clear that western influences were what shaped the Assamese plays into their perfection. After independence, Assamese writers of prose, poetry, and theatre, produced works that were on pace with the period. It demonstrated identical compositional experimentation and sociological analysis. The Assamese plays exhibit a strong western heritage from playwrights like Ibsen, Shaw, Beckett, and other absurd dramatists. A few dramatists, like Dr. Arun Sarma, Ratna Ojha, and Himendrakumar Borthakur made reflections of works of Lonesco and Beckett and despite the fact the impact of absurd dramas was not very common. In this article, the researcher investigated the works of the most renowned and esteemed Assamese playwright, Dr. Arun Sarma (1964), to emphasize the distinguishing components and similarities of Shri Nibaran Bhattacharya and Aahaar with those of absurd dramatic tropes. The researcher discovered, using the comparative technique of analysis, that, despite frequent assertions to the contrary, Aahaar has much in common with the absurdist movement, whereas Shri Nibaran Bhattacharya cannot be regarded as a fully-fledged absurd drama
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