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51.
Microchimica Acta - The authors describe a lysozyme aptasensor based on the use of gold nanoparticles (AuNP) assembled on the carbon nanotubes, graphene oxide and chitosan. An electrochemical... 相似文献
52.
Thomas L. Warren Stewart A. Silling Abe Askari Olaf Weckner Michael A. Epton Jifeng Xu 《International Journal of Solids and Structures》2009,46(5):1186-1195
In this paper, we develop a new non-ordinary state-based peridynamic method to solve transient dynamic solid mechanics problems. This new peridynamic method has advantages over the previously developed bond-based and ordinary state-based peridynamic methods in that its bonds are not restricted to central forces, nor is it restricted to a Poisson’s ratio of 1/4 as with the bond-based method. First, we obtain non-local nodal deformation gradients that are used to define nodal strain tensors. The deformation gradient tensors are used with the nodal strain tensors to obtain rate of deformation tensors in the deformed configuration. The polar decomposition of the deformation gradient tensors are then used to obtain the nodal rotation tensors which are used to rotate the rate of deformation tensors and previous Cauchy stress tensors into an unrotated configuration. These are then used with conventional Cauchy stress constitutive models in the unrotated state where the unrotated Cauchy stress rate is objective. We then obtain the unrotated Cauchy nodal stress tensors and rotate them back into the deformed configuration where they are used to define the forces in the nodal connecting bonds. As a first example we quasi-statically stretch a bar, hold it, and then rotate it ninety degrees to illustrate the methods finite rotation capabilities. Next, we verify our new method by comparing small strain results from a bar fixed at one end and subjected to an initial velocity gradient with results obtained from the corresponding one-dimensional small strain analytical solution. As a last example, we show the fracture capabilities of the method using both a notched and un-notched bar. 相似文献
53.
James M. Kelly Thomas M. Jeitner Nicole N. Waterhouse Wenchao Qu Ethan J. Linstad Banafshe Samani Clarence Williams Jr. Anastasia Nikolopoulou Alejandro Amor-Coarasa Stephen G. DiMagno John W. Babich 《Molecules (Basel, Switzerland)》2022,27(5)
Cancer cells require lipids to fulfill energetic, proliferative, and signaling requirements. Even though these cells can take up exogenous fatty acids, the majority exhibit a dependency on de novo fatty acid synthesis. Fatty acid synthase (FASN) is the rate-limiting enzyme in this process. Expression and activity of FASN is elevated in multiple cancers, where it correlates with disease progression and poor prognosis. These observations have sparked interest in developing methods of detecting FASN expression in vivo. One promising approach is the imaging of radiolabeled molecular probes targeting FASN by positron emission tomography (PET). However, although [11C]acetate uptake by prostate cancer cells correlates with FASN expression, no FASN-specific PET probes currently exist. Our aim was to synthesize and evaluate a series of small molecule triazolones based on GSK2194069, an FASN inhibitor with IC50 = 7.7 ± 4.1 nM, for PET imaging of FASN expression. These triazolones were labeled with carbon-11 in good yield and excellent radiochemical purity, and binding to FASN-positive LNCaP cells was significantly higher than FASN-negative PC3 cells. Despite these promising characteristics, however, these molecules exhibited poor in vivo pharmacokinetics and were predominantly retained in lymph nodes and the hepatobiliary system. Future studies will seek to identify structural modifications that improve tumor targeting while maintaining the excretion profile of these first-generation 11C-methyltriazolones. 相似文献
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Leonova MA Askari JA Gordon KN Krisch AD Liu J Morozov VS Nees DA Raymond RS Sivers DW Wong VK Hinterberger F 《Physical review letters》2012,108(7):074801
Spin resonances can depolarize or spin flip a polarized beam. We studied 1st and higher order spin resonances with stored 2.1 GeV/c vertically polarized protons. The 1st order vertical (ν(y)) resonance caused almost full spin flip, while some higher order ν(y) resonances caused partial depolarization. The 1st order horizontal (ν(x)) resonance caused almost full depolarization, while some higher order ν(x) resonances again caused partial depolarization. Moreover, a 2nd order ν(x) resonance is about as strong as some 3rd order ν(x) resonances, while some 3rd order ν(y) resonances are much stronger than a 2nd order ν(y) resonance. One thought that ν(y) spin resonances are far stronger than ν(x), and that lower order resonances are stronger than higher order; the data do not support this. 相似文献
57.
Synthesis of SAPO-34 nanocrystals which has been recently considered as a challenging task was successfully performed by sonochemical method using TEAOH as structure directing agent (SDA). The products were characterized by XRD, SEM, EDX, BET and TGA. The average crystal size of the final product prepared sonochemically is 50 nm that is much smaller than that of synthesized under hydrothermal condition and the morphology of the crystals changes from uniform spherical nanoparticles to spherical aggregates of cube type SAPO-34 crystals respectively. In the case of sample synthesized sonochemically with aid of hydrothermal condition, the surface area is significantly upper than that of obtained by the conventional static hydrothermal technology with almost the same crystallinity. SAPO-34 framework synthesized by just ultrasonic treatment is unstable and a significant part of SAPO-34 nanocrystals is transformed to the dense phase of AlPO4 structure, i.e., Cristobalite. Contrary to hydrothermal method that at least 24 h of the synthesis time is required to obtain fully crystalline SAPO-34, sonochemical-assisted hydrothermal synthesis of samples leads to form fully crystalline SAPO-34 crystals taking only 1.5 h. In a sonochemical process, a huge density of energy for crystallization is provided by the collapse of bubbles which formed by ultrasonic waves. The fact that small SONO-SAPO-34 crystals could be prepared by the sonochemical method suggests a high nucleation density in the early stages of synthesis and slow crystal growth after nucleation. 相似文献
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Parvin Askari Ali Faraji Gholamreza Khayatian Sajjad Mohebbi 《Journal of the Iranian Chemical Society》2017,14(3):613-621
A series of new (MgO) x CuO and (MgO) x MnO2 nanocomposites were prepared and used as adsorbent for removal of As3+, Hg2+, and Pb2+ ions from aqueous solution with high capacity and detection limit. These nanocomposites were synthesized with different molar ratios by sonochemical method in alkaline solution using polyvinylpyrrolidone as a capping agent and were characterized by FTIR, AAS, UV–Vis spectroscopy, and TEM and SEM imaging. The maximum heavy metal ions adsorption was achieved for (MgO)0.32CuO and (MgO)2.9MnO2 nanocomposites assisted by 3-min sonication using ultrasound. Adsorbent capacity of (MgO)0.32CuO reached 500.0 mg/g and detection limit was 0.1 ppb for As3+. Also (MgO)2.9MnO2 nanocomposite adsorbed 457.1 mg/g of Hg2+ and 461.2 mg/g of Pb2+. Extremely low detection limits of 1.5 and 2.0 ppb were obtained for Hg(II) and Pb(II) ions, respectively, which are much lower than the WHO allowable limits. So, these nanocomposites should be excellent candidate for heavy metal removal with advantage of high capacity, high sensitivity, cost effectiveness and easy preparation. 相似文献
60.
Banafshe Samani Ghaleh Taki Mahbubeh Rostami Valiollah Mirkhani Majid Moghadam Iraj Mohammadpoor‐Baltork Shahram Tangestaninejad Ahmad Jamali Moghadam Reza Kia 《Journal of heterocyclic chemistry》2015,52(6):1848-1857
In the present work, a simple, green, rapid, and catalyst‐free procedure for the synthesis of benzamide derivatives by ring opening of azlactones with diamines such as ethylene diamine and 1,3‐propylenediamine is described. The present method offers several advantages such as short reaction times, easy work‐up, and mild reaction conditions in the absence of catalyst and any toxic solvent and material. In addition, the structure obtained by X‐ray crystallography was compared with the theoretical results obtained by density functional theory using the B3LYP functional and cc‐pVDZ basis sets. 相似文献