4,041 research outputs found

    A Tribe Called Trump: The Motivation Behind the Education Line & Why People of Color Voted for the Bully-in-Chief

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    Throughout the 2020 election, a constant question arose, “How can they vote for Trump?” Within the context of tribalism and the disenfranchised status created by the deteriorated blue-collar job market, I reflect on labor history to explain how those who are denied affordable education are left out of the American dream. This trend disproportionately affects the Black community. In turn, these populations potentially remain reminiscent of how America was great for them in the past. Supported by descriptive statistics, I reflect on the educational line in red and contested states during the 2020 presidential election. The paper concludes with the recommendation that higher education must be affordable to help communities transcend the dream of manufacturing but instead embrace a well-informed position in supporting our democracy

    Positron Lifetime As A Function Of Grain Size

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    Published data on positron annihilation lifetime in copper as a function of grain size have been analyzed to show that there is a linear relationship between the internal grain boundary surface area, per unit volume, S v, and the positron lifetime, τ. The analysis indicates that grain boundaries are important in the trapping of positrons. It is suggested that the slope of the resulting straight line, dS v/dτ, can be used to determine the annihilation rate of the grain boundaries. © 1977 Springer-Verlag

    NANOCRYSTALS OF CHEMOTHERAPEUTIC AGENTS FOR CANCER THERANOSTICS: DEVELOPMENT AND IN VITRO AND IN VIVO EVALUATION

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    The majority of pharmacologically active chemotherapeutics are poorly water soluble. Solubilization enhancement by the utilization of organic solvents often leads to adverse side effects. Nanoparticle-based cancer therapy, which is passively targeted to the tumor tissue via the enhanced permeation and retention effect, has been vastly developed in recent years. Nanocrystals, which exist as crystalline and carry nearly 100% drug loading, has been explored for delivering antineoplastic agents. Additionally, the hybrid nanocrystal concept offers a novel and simple way to integrate imaging agents into the drug crystals, enabling the achievement of theranostics. The overall objective of this dissertation is to formulate both pure and hybrid nanocrystals, evaluate their performance in vitro and in vivo, and investigate the extent of tissue distribution and tumor accumulation in a murine model. Pure and hybrid nanocrystals of several model drugs, including paclitaxel (PTX), camptothecin, and ZSTK474, were precipitated by the antisolvent method in the absence of stabilizer, and their size was further minimized by homogenization. The nanocrystals of PTX, which is the focus of the study, had particle size of approximately 200 nm and close-to-neutral surface charge. Depending on the cell type, PTX nanocrystals exerted different level of cytotoxicity. In human colon and breast cancer xenograft models, nanocrystals yielded similar efficacy as the conventional formulation, Taxol, at a dose of 20 mg/kg, yet induced a reduced toxicity. Biodistribution study revealed that 3H-PTX nanocrystals were sequestered rapidly by the macrophages upon intravenous injection. Yet, apparent toxicity was not observed even after four weekly injections. The sequestered nanocrystals were postulated to be released slowly into the blood circulation and reached the tumor. Tritium-labeled-taxol, in contrast, was distributed extensively to all the major organs, inducing systemic toxicity as observed in significant body weight loss. The biodistribution results obtained from radioactive analysis and whole-body optical imaging was compared. To some degree, the correlation was present, but divergence in the quantitative result, due to nanocrystal integrity and limitations associated with the optical modality, existed. Despite their promising properties, nanocrystal suspensions must be securely stabilized by stealth polymers in order to minimize opsonization, extend blood-circulation time, and efficiently target the tumor

    Void-strengthening In Aluminum And Its Nature

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    Temperature and strain rate dependence of yield strength were used to analyze the nature of aluminum strengthened by the formation of voids. Aluminum rods 99.999% pure were quenched and heat treated to form voids with an approximate density of 1013-1014 voids/cm3. Voids in selected samples were observed by electron microscopy. The yield strength of the void strengthened samples was measured at various temperatures from 77 to 593 K and at two strain rates, 3.33 x 10-2/s and 1.67 x 10-3/s. Tests at room temperature and at 77 K were made at various strain rates. The similarity of Coulomb\u27s approach to void strengthening and that of Orowan stress with Ashby\u27s dipole criterion was observed, and it was determined that the extent and effectiveness of void strengthening depends primarily on void density and much less on void size. The amount of strengthening obtained at room temperature was found to be consistent with the estimates. Compared to annealed aluminum, void strengthened aluminum is more susceptible to the instability of plastic flow at low temperatures; its temperature dependence of yield strength varies in different temperature ranges and shows a higher strain rate sensitivity of yield strength. © 1976

    Laboratory and tentative interstellar detection of trans-methyl formate using the publicly available Green Bank Telescope PRIMOS survey

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    The rotational spectrum of the higher-energy trans conformational isomer of methyl formate has been assigned for the first time using several pulsed-jet Fourier transform microwave spectrometers in the 6-60 GHz frequency range. This species has also been sought toward the Sagittarius B2(N) molecular cloud using the publicly available PRIMOS survey from the Green Bank Telescope. We detect seven absorption features in the survey that coincide with laboratory transitions of trans-methyl formate, from which we derive a column density of 3.1 (+2.6, -1.2) \times 10^13 cm-2 and a rotational temperature of 7.6 \pm 1.5 K. This excitation temperature is significantly lower than that of the more stable cis conformer in the same source but is consistent with that of other complex molecular species recently detected in Sgr B2(N). The difference in the rotational temperatures of the two conformers suggests that they have different spatial distributions in this source. As the abundance of trans-methyl formate is far higher than would be expected if the cis and trans conformers are in thermodynamic equilibrium, processes that could preferentially form trans-methyl formate in this region are discussed. We also discuss measurements that could be performed to make this detection more certain. This manuscript demonstrates how publicly available broadband radio astronomical surveys of chemically rich molecular clouds can be used in conjunction with laboratory rotational spectroscopy to search for new molecules in the interstellar medium.Comment: 40 pages, 7 figures, 4 tables; accepted for publication in Ap

    MorgantinaVR: Cityscale Handheld AR and Cross–Platform VR for Visualizing Georeferenced Archaeological Datasets

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    The use of Augmented and Virtual Reality in cultural heritage has increased dramatically in recent years, with uses that go far beyond creating and displaying digital reconstructions for museum visitors and tourists. This paper describes the collaboration between Archimedes Digital and the Contrada Agnese Project (CAP) to develop a framework and suite of applications to support the examination display of archaeological data from the site of Morgantina, Sicily in VR and AR. Primary purposes of this digital approach include facilitating collaboration between CAP’s specialists (archaeological, geospatial, and museum), and enabling the effective dissemination of data to researchers and to the general public

    The Oxidation Of Dilute Alloys Of Magnesium In Aluminium

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    The oxide layers developed during the oxidation of aluminum alloys containing 500 and 1000 PPM of magnesium at 850K were examined with the aid of electron spectroscopy for chemical analysis. The magnesium content of the oxide layers was relatively high because of the preferential depletion of the magnesium atoms from the base alloys. Near the outer surfaces of the oxide layers, spinel (MgAl2O4) was the predominant magnesium-bearing compound. At depth, MgO was more dominant. The preferential depletion of magnesium from the alloys injected vacancies into the material. This led to the formation of defect clusters. The presence of these defect clusters explains the experimental observations reported earlier by other researchers
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