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91.
Huseyin Riza Ferhat Karabulut Berk Mert Cagatay Altinkok Ali Osman Karatavuk Gokhan Acik Murat Turkyilmaz 《先进技术聚合物》2021,32(1):220-227
In this article, the study on the swelling and thermal behaviors of a new series of bile acid‐based polymeric hydrogels is reported. For this purpose, in the first step, the reduction of carboxyl acid groups of some common bile acids including cholic acid (CA), chenodeoxy cholic acid (CDCA), and lithocholic acid (LCA) to the corresponding alcohols by lithium aluminum hydride (LiAlH4) in THF solution is performed. Then, hydroxyl functionalities of the obtained products are reacted with the acryloyl chloride in the presence of triethylamine (TEA). Finally, the cross‐linking reactions between acryloyl functionalized bile acids and methoxy poly(ethylene glycol) monomethacrylate (MPEGMA) are conducted by free‐radical photo‐polymerization technique at λ = 350 nm in the presence of 2,2‐Dimethoxy‐2‐phenylacetophenone (DMPA) as an initiator to achieve the desired bile acid‐based polymeric hydrogels. The resulting hydrogels and their intermediates are characterized by Fourier transform infrared (FT‐IR) and Proton nuclear magnetic resonance (1H‐NMR) spectroscopies. The swelling and thermal behavior of the obtained hydrogels indicates that the hydrogel starting from cholic acid is more swellable and has enhanced thermostability compared to others. Thus, the results of this study offer beneficial insights to researchers working in particularly bio‐medical industry. 相似文献
92.
Although commercial screen-printed electrodes (SPEs) are used extensively for biosensor purposes nowadays, detailed studies on characterization are still limited. In this study, the surface of the gold-based screen-printed electrode (SPGE) was carefully modified with self-assembly-monolayer through an optimized immobilization procedure. The key physical and chemical properties with regeneration capacity of the developed biosensors were assessed by various characterization techniques. Then SPGE was used to determine its sensitivity, limit of detection (LOD) and limit of quantification (LOQ) for a toxin substance of domoic acid in seafood that has become more common and rising concern of marine wildlife and seawater pollution. LOD in phosphate buffered saline (PBS) and cell culture media were obtained as 2.93 ng mL−1 and 4.28 ng mL−1, respectively. The reduced sensitivity for antibody-based biosensors in the cell culture medium was probably due to interaction of nonspecific compounds with DA in the culture medium compared to the much less complex environment of PBS. In addition, the regeneration capacity has been found very limited due to inherent heterogeneity and low robustness. This study can be used for the main challenges with the design requirements of commercial SPE-based biosensors to provide a detailed perspective for further toxicity studies. 相似文献
93.
94.
The crystal structure of [(n-C4H9)4N]2[Pt2I6] has been determined from X-ray data measured by counter methods. It crystallizes in the monoclinic space groupP21/c (C
2h
-5
, No. 14) with unit cell constantsa=14.457(4),b=14.036(4),c=23.696(5) Å,=101.02(3)°, andD
c
=2.30 g cm–3 forZ=4. Full-matrix least-squares refinement led to a finalR value of 0.049 for 1786 independent observed reflections. The [Pt2I6]2– anion is planar to within 0.07 Å and exhibits an average Pt-I bridging bond length of 2.559(4) Å and average Pt-I terminal distance of 2.571(7) Å. Of the two independent [(n-C4H9)4N]+ cations, one approaches a ¯42m-D
2d
conformation, the other an approximate ¯4-S4 conformation. 相似文献
95.
In this paper, an algebraic approach is presented for determiningthe normal forms of four-dimensional systems with a nilpotentlinear part. Certain transformations introduced in this caseresult in a simplified procedure for the calculation of normalforms. Thus, one does not need to solve a series of partialdifferential equations as usually required by the normal-formtheory; indeed, algebraic calculations are sufficient. The approachcan be applied to higher-order systems with a nilpotent linearpart as well. To illustrate the new approach, five examplesare presented. Normal forms and the associated coefficientsof two physical systems, an electric network and a mechanicalsystem, are fully analyzed. 相似文献
96.
A new class of phosphorus-containing 1,3-dipoles can be generated by the multicomponent reaction of aldehydes, acid chlorides and the phosphonite PhP(catechyl). These 1,3-dipoles are formally cyclic tautomers of simple Wittig-type ylides, where the angle strain and moderate nucleophilicity in the catechyl-phosphonite favor their cyclization and also direct 1,3-dipolar cycloaddition to afford single regioisomers of substituted products. Coupling the generation of the dipoles with 1,3-dipolar cycloaddition offers a unique, modular route to furans from combinations of available aldehydes, acid chlorides and alkynes with independent control of all four substituents.A new class of phosphorus-containing 1,3-dipoles has been developed, which, when coupled with cycloaddition, offers modular synthesis of furans with independent control of all four substituents. 相似文献
97.
Some novel applications of certain higher order ordinary complex differential equations to normalized analytic functions 下载免费PDF全文
The aim of this work is first to reveal some nonlinear connections between normalized analytic functions and certain higher order ordinary(complex) differential equations and then to point some of their geometric implications appertaining to normalized analytic functions out. 相似文献
98.
Adil Tolga Gorgulu Huseyin Cankaya Adnan Kurt Adolfo Speghini Marco Bettinelli Alphan Sennaroglu 《Journal of luminescence》2012,132(1):110-113
We have performed detailed experiments to investigate the spectroscopic properties of a new type of tellurite based host doped with thulium: Tm2O3:(0.70)TeO2–(0.15)K2O–(0.15)Nb2O5 having Tm2O3 concentrations of 0.125, 0.25, 0.5, and 1.0 mol%. By performing a Judd–Ofelt analysis of the absorption bands, we obtained average radiative lifetimes of 2.57±0.20 and 0.35±0.01 ms for the 3H4 and 3F4 levels, respectively. Furthermore, we also observed that an increase in the Tm2O3 concentration from 0.125 to 1.0 mol% results in a decrease of the measured fluorescence lifetime from 814 to 439 μs and from 258 to 47 μs for the 3H4 and 3F4 levels, respectively, due to efficient non-radiative decay. The highest quantum efficiency of 32% was obtained for the sample doped with 0.125 mol% Tm2O3 for the 3H4 level. Results show that cross relaxation becomes important as the ion concentration is increased, leading to the quenching of the 1460-nm band and enhancement of the 1860-nm emission. The highest emission cross section of 6.85×10?21 cm2 measured for the 1860-nm band reveals the potential of this host for the development of 2-μm lasers in bulk glass as well as fiber media. 相似文献
99.
F. Talay Akyildiz Dennis A. Siginer Huseyin Kaplan 《Communications in Nonlinear Science & Numerical Simulation》2012,17(1):35-44
Start-up thin film flow of fluids of grade three over a vertical longitudinally oscillating solid wall in a porous medium is investigated. The governing non-linear partial differential equation representing the momentum balance is solved by the Fourier-Galerkin approximation. The effect of the porosity, material constants as well as oscillations on the drainage rate and flow enhancement is explored and clarified. 相似文献
100.
Synthesis and characterization of polyphenylenes with polypeptide and poly(ethylene glycol) side chains 下载免费PDF全文
Huseyin Akbulut Takeshi Endo Shuhei Yamada Yusuf Yagci 《Journal of polymer science. Part A, Polymer chemistry》2015,53(15):1785-1793
We report a novel approach for fabrication of multifunctional conjugated polymers, namely poly(p‐phenylene)s (PPPs) possessing polypeptide (poly‐l ‐lysine, PLL) and hydrophilic poly(ethylene glycol) (PEG) side chains. The approach is comprised of the combination of Suzuki coupling and in situ N‐carboxyanhydride (NCA) ring‐opening polymerization (ROP) processes. First, polypeptide macromonomer was prepared by ROP of the corresponding NCA precursor using (2,5‐dibromophenyl)methanamine as an initiator. Suzuki coupling reaction of the obtained polypeptide and PEG macromonomers both having dibromobenzene end functionality using 1,4‐benzenediboronic acid as the coupling partner in the presence of palladium catalyst gave the desired polymer. A different sequence of the same procedure was also employed to yield polymer with essentially identical structure. In the reverse sequence mode, low molar mass monomer (2,5‐dibromophenyl)methanamine, and PEG macromonomer were coupled with 1,4‐benzenediboronic acid in a similar way followed by ROP of the L‐Lysine NCA precursor through the primary amino groups of the resulting polyphenylene. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015 , 53, 1785–1793 相似文献