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41.
Fatemeh Davar Masoud Salavati-Niasari Sotirios Baskoutas 《Applied Surface Science》2011,257(9):3872-3877
Strontium carbonate nanorods have been successfully synthesized via solid-state decomposition of a new precursor, [Sr(Pht)(H2O)2]. The obtained nanorods were found to be orthorhombic with the length of 70-100 nm and the diameter of about 10-15 nm. The Effect of calcinations temperature on morphology and purity of the products has been investigated. Strontium carbonate nanorods were formed at 500 °C. The products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Fourier transform infrared (FT-IR) spectroscopy. In addition, further evidence for the purity and stoichiometry of the product was obtained by XPS (X-ray photoelectron spectroscopy) spectrum. 相似文献
42.
Eleftherios Lavdas Panayiotis Mavroidis Theofilos Topaltzikis Vasileios Slatinopoulos Violeta Roka Anna Vlachopoulou Nikos Papanikolaou Sotirios Stathakis Eftichia Kapsalaki Georgios Batsikas 《Magnetic resonance imaging》2013
The purpose of this study is to report the significant differences found in the identification of lesions in cervical spinal cord of two patients with multiple sclerosis when using the BLADE T2-TSE and BLADE T2-TIRM sequences as opposed to the conventional T2-TSE and T2-TIRM sequences for sagittal acquisition at 1.5 T. In both patients, one more lesion was identified with the BLADE sequences than with the conventional ones. Consequently, we suggest the use of BLADE T2-TSE and BLADE T2-TIRM sequences in place of conventional ones for sagittal examination of the cervical spinal cord of multiple sclerosis patients. The advantages of ΤΙRΜ to reveal the pathology of the cervical spinal cord and the advantage of BLADE sequences to improve image quality should be combined in a sequence that could be ideal for cervical spinal cord examinations. 相似文献
43.
44.
Sotirios Bonanos 《Communications in Mathematical Physics》1972,26(4):259-270
The stability of a class of homogeneous cosmological models is investigated. It is shown that the perturbation problem for six such universes can be reduced to a system of ordinary differential equations. The time development of the perturbations is such that they remain finite at all times for which the unperturbed metric is non-singular.Work supported in part by the National Science Foundation. 相似文献
45.
Christos Kokkinos Mamas Prodromidis Anastasios Economou Panagiota Petrou Sotirios Kakabakos 《Analytica chimica acta》2015
A novel immunosensor based on graphite screen-printed electrodes (SPEs) modified with bismuth citrate was developed for the voltammetric determination of C-reactive protein (CRP) in human serum using quantum dots (QDs) labels. The sandwich-type immunoassay involved physisorption of CRP capture antibody on the surface of the sensor, sequential immunoreactions with CRP and biotinylated CRP reporter antibody and finally reaction with streptavidin-conjugated PbS QDs. The quantification of the target protein was performed with acidic dissolution of the PbS QDs and anodic stripping voltammetric detection of the Pb(II) released. Detection was performed at bismuth nanodomains formed on the sensor surface during the electrolytic preconcentration step, as bismuth citrate was reduced to metallic bismuth simultaneously with the deposition of Pb on the surface of the immunosensor. Under optimal conditions, the response was linear over the range 0.2–100 ng mL−1 CRP and the limit of detection was 0.05 ng mL−1 CRP. Since the modified SPE serves as both the biorecognition element and the QDs reader, the analytical procedure is simplified, the drawbacks of existing electroplated immunosensors are minimized while the proposed disposable sensing platform provides convenient, low-cost and ultrasensitive detection of proteins and wider scope for mass-production. 相似文献
46.
Integrated Deadenylase Genetic Association Network and Transcriptome Analysis in Thoracic Carcinomas
Athanasios Kyritsis Eirini Papanastasi Ioanna Kokkori Panagiotis Maragozidis Demetra S. M. Chatzileontiadou Paschalina Pallaki Maria Labrou Sotirios G. Zarogiannis George P. Chrousos Dimitrios Vlachakis Konstantinos I. Gourgoulianis Nikolaos A. A. Balatsos 《Molecules (Basel, Switzerland)》2022,27(10)
47.
Sotirios Nik. Longinos Dionisia Dimitra Longinou Nurbala Myrzakhmetova Nazgul Akimbayeva Mariamkul Zhursumbaeva Kaldibek Abdiyev Zhexenbek Toktarbay Mahmut Parlaktuna 《Molecules (Basel, Switzerland)》2022,27(14)
Heat generation during gas hydrate formation is an important problem because it reduces the amount of water and gas that become gas hydrates. In this research work, we present a new design of an impeller to be used for hydrate formation and to overcome this concern by following the hydrodynamic literature. CH4 hydrate formation experiments were performed in a 5.7 L continuously stirred tank reactor using a butterfly turbine (BT) impeller with no baffle (NB), full baffle (FB), half baffle (HB), and surface baffle (SB) under mixed flow conditions. Four experiments were conducted separately using single and dual impellers. In addition to the estimated induction time, the rate of hydrate formation, hydrate productivity and hydrate formation rate, constant for a maximum of 3 h, were calculated. The induction time was less for both single and dual-impeller experiments that used full baffle for less than 3 min and more than 1 h for all other experiments. In an experiment with a single impeller, a surface baffle yielded higher hydrate growth with a value of 42 × 10−8 mol/s, while in an experiment with dual impellers, a half baffle generated higher hydrate growth with a value of 28.8 × 10−8 mol/s. Both single and dual impellers achieved the highest values for the hydrate formation rates that were constant in the full-baffle experiments. 相似文献
48.
Costas Tsioptsias Christina Spartali Sotirios I. Marras Xanthi Ntampou Ioannis Tsivintzelis Costas Panayiotou 《Molecules (Basel, Switzerland)》2022,27(19)
Silybin is a complex organic molecule with high bioactivity, extracted from the plant Silybum. As a pharmaceutical substance, silybin’s bioactivity has drawn considerable attention, while its other properties, e.g., thermodynamic properties and thermal stability, have been less studied. Silybin has been reported to exhibit a melting point, and values for its heat of fusion have been provided. In this work, differential scanning calorimetry, thermogravimetry including derivative thermogravimetry, infrared spectroscopy, and microscopy were used to provide evidence that silybin exhibits a thermochemical transition, i.e., softening occurring simultaneously with decomposition. Data from the available literature in combination with critical discussion of the results in a general framework suggest that thermochemical transition is a broad effect exhibited by various forms of matter (small molecules, macromolecules, natural, synthetic, organic, inorganic). The increased formation of hydrogen bonding contributes to this behavior through a dual influence: (a) inhibition of melting and (b) facilitation of decomposition due to weakening of chemical bonds. 相似文献
49.
Nicolas Brosse Alain Durmus Éric Moulines Sotirios Sabanis 《Stochastic Processes and their Applications》2019,129(10):3638-3663
In this article, we consider the problem of sampling from a probability measure having a density on proportional to . The Euler discretization of the Langevin stochastic differential equation (SDE) is known to be unstable, when the potential is superlinear. Based on previous works on the taming of superlinear drift coefficients for SDEs, we introduce the Tamed Unadjusted Langevin Algorithm (TULA) and obtain non-asymptotic bounds in -total variation norm and Wasserstein distance of order 2 between the iterates of TULA and , as well as weak error bounds. Numerical experiments are presented which support our findings. 相似文献
50.
Multi-spanning integral membrane proteins, including G-protein coupled receptors (GPCR), ion channels, and ion transporters, comprise a major class of drug targets. However, despite their vital importance, most molecular structures of membrane proteins remain elusive. This is largely due to lack of effective materials and methods to stabilize their functional conformation for sufficient time. Thus finding optimal surfactants and developing new approaches to study fundamental properties of unstable membrane proteins is urgently needed. In this tutorial review we summarize designer peptides with surfactant properties and their usefulness to stabilize membrane proteins. These peptide surfactants present new opportunities for the stabilization and characterization of diverse membrane proteins. Previous studies on the interaction between surfactant peptides and membrane proteins revealed strategies to design new peptides tailor-made for the stabilization of specific proteins. We review examples of solubilization, purification, long-term stabilization of membrane proteins, and the design principles of peptide sequences. We discuss future trends for exploiting spatial features, thermodynamic parameters, and self-assembling properties to create peptide surfactant structures to facilitate the characterization of diverse membrane proteins. 相似文献