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1.
Anna Stasiowicz Natalia Rosiak Ewa Tykarska Maciej Kozak Jacek Jenczyk Piotr Szulc Joanna Kobus-Cisowska Kornelia Lewandowska Anita Paziska Wojciech Paziski Judyta Cielecka-Piontek 《International journal of molecular sciences》2021,22(8)
Piperine is an alkaloid that has extensive pharmacological activity and impacts other active substances bioavailability due to inhibition of CYP450 enzymes, stimulation of amino acid transporters and P-glycoprotein inhibition. Low solubility and the associated low bioavailability of piperine limit its potential. The combination of piperine with 2-hydroxypropyl-β-cyclodextrin (HP-β-CD) causes a significant increase in its solubility and, consequently, an increase in permeability through gastrointestinal tract membranes and the blood–brain barrier. X-ray powder diffraction (XRPD), differential scanning calorimetry (DSC), Fourier-transform infrared spectroscopy (FT-IR), nuclear magnetic resonance (NMR) were used to characterize interactions between piperine and HP-β-CD. The observed physicochemical changes should be combined with the process of piperine and CD system formation. Importantly, with an increase in solubility and permeability of piperine as a result of interaction with CD, it was proven to maintain its biological activity concerning the antioxidant potential (2,2-diphenyl-1-picryl-hydrazyl-hydrate assay), inhibition of enzymes essential for the inflammatory process and for neurodegenerative changes (hyaluronidase, acetylcholinesterase, butyrylcholinesterase). 相似文献
2.
3.
Stawarz Sylwester Witek Natalia Kucharczyk Wojciech Bakar Mohamed Stawarz Magdalena 《International Journal of Mechanics and Materials in Design》2019,15(3):585-599
International Journal of Mechanics and Materials in Design - The present work investigates the ablative and thermal properties of an epoxy resin which was modified with titanium dioxide... 相似文献
4.
JM Rodríguez J Arias Díaz C García Carreras J Torres Melero JL Balibrea 《Canadian Metallurgical Quarterly》1994,9(5):304-310
Reaction of bacterial adhesins with complementary receptors on the surfaces of mucosal respiratory, gastrointestinal and genitourinary cells leads to bacterial adhesion to the human body. This is the first step in the sequence of events leading to infection. It has been observed that subinhibitory concentrations (sub-MICs) of some antibiotics are able to reduce bacterial adhesion. The pharmacokinetic curves of antibiotics show that these sub-MICs are present in tissues during a typical course of therapy. This study investigated the ability of sub-MICs of seven macrolides and four fluoroquinolones to reduce adhesiveness of Staphylococcus aureus to human buccal cells. The literature generally reports data for only one antibiotic at a time. To obtain an overall view of the findings of eleven antibiotics together, the data have been normalized according to the molecular weight of each antibiotic and the dose-effect curves determined. 相似文献
5.
Natalia Andronova 《Polymer》2005,46(18):6746-6755
The synthesis and characterization of degradable polymeric networks for biomedical applications was performed. Cross-linked films of poly(ε-caprolactone) (PCL) and poly(1,5-dioxepan-2-one) (PDXO) having various mole fractions of monomers and different cross-link densities were successfully prepared using 2,2′-bis-(ε-caprolactone-4-yl) propane (BCP) as cross-linking agent. Reaction parameters were carefully examined to optimise the film-forming conditions. Networks obtained were elastomeric materials, easy to cast and remove from the mould. Effect of CL content and cross-link density on the final properties of the polymer network was evaluated. High CL content or degree of cross-linking led to increase in Young's modulus and decrease in elongation at break. An increase in crystalline domains in films having a higher CL content was observed by optical microscopy. A greater thermal stability was observed in films having a high CL content. The hydrophilicity of the materials could be tailored by changing the CL content. The surface of the films became rougher with higher CL content. 相似文献
6.
This paper shows a few possibilities for the application of Community OR in a Third World country based on experience in Venezuela. These possibilities are discussed in a framework of the relationship between the state and community organizations. Emphasis lies in showing that Community OR in Venezuela requires a deep critical commitment to emancipation in order to help community organizations develop in a rather hostile environment. Lastly, results in dealing with community organizations in Venezuela using the Interpretive Systemology approach are presented. 相似文献
7.
M. Zandian J. G. Pasko J. M. Arias R. E. De Wames S. H. Shin 《Journal of Electronic Materials》1995,24(5):681-684
Measurements of 77K RoA and 300K reverse bias dynamic impedance (RdA) products at one volt reverse bias has been carried out to assess the degree of correlation of this figure of merit. Planar
P-on-n heterostructures were grown on near lattice-matched CdZnTe substrates with Hg1-xCdxTe (0.20< x <0.30) by molecular beam epitaxy. These devices were passivated with CdTe and doped with indium and arsenic as
n- and p-type dopants, respectively. Current-voltage characteristic of these devices exhibit thermally generated dark currents
at small and modest reverse bias. We have observed that RoA values of these long wavelength infrared P-on-n heterostructure photodiodes at 77K correlate with room temperature RdA values. Diode arrays with high room temperature RdA values at one volt reverse bias also have high RoA values at 77K. Similarly, low RdA values at room temperature indicate poor performance at 77K where deviation from diffusion current occurs at reverse bias
of 0.2 to 1 volt at room temperature. The results presented here, for a small samples of devices, demonstrate that room temperature
measurements of current-voltage characteristics to evaluate Hg1-xCdxTe (0.22< x <0.28) diode performance and array uniformity at lower temperatures can be used. This provides an acceptable criteria
for further study at lower temperatures. 相似文献
8.
We carried out the analysis of lecithins with a common polar group and paraffin chains of different lengths and degree of saturation at two levels, namely: (a) that of the paraffin chain proper, by studying whether structural defects arising from the different mobility of the lipid chains affected their rheological properties; and (b) that of the polar group, which is known to be affected by perturbations to the paraffin chain, and so should its ionization. 相似文献
9.
A novel approach is presented to calculate the sensitivities of the scattering parameters of microwave filters obtained with the full‐wave mode‐matching (MM) technique. Using only the MM simulation of the original network, the sensitivities of the scattering parameters with respect to all designable parameters are obtained. The adjoint network method (ANM) is applied to the generalized scattering matrices of the different filter components. This guarantees good accuracy of the calculated sensitivities. The implementation details are discussed for N‐resonator ridge waveguide filters. Excellent agreement is obtained between the sensitivities calculated using ANM and those obtained using the expensive central differences. © 2006 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2006. 相似文献
10.
Kiss P. Arias J. Li D. Boccuzzi V. 《IEEE transactions on circuits and systems. I, Regular papers》2004,51(1):200-205
Stability analysis of high-order delta-sigma loops is a challenge. In this brief, a sufficient design criterion is presented for high-order multibit error-feedback digital-to-analog converters (DACs) which are especially suitable for high-speed operation. This analytical criterion might be too conservative, but it allows for the design of stable, robust, and high-resolution delta-sigma DACs. Both analytical and numerical analysis are performed for verification. Also, experimental results of a discrete-component multiplier-free prototype demonstrate 10-b operation at a very low oversampling ratio of 4. 相似文献