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31.
Uğur Oflaz Fatma Yurt Lambrecht Osman Yilmaz Çetin Pekçetin 《Journal of Radioanalytical and Nuclear Chemistry》2013,295(2):959-964
This study aims to investigate effects of adenine on bacterial translocation (BT) using 99mTc-labeled E. coli in an intestinal obstruction rat model. In the study twenty-one rats were used. The rats were divided into three groups according to different feeding patterns. The control group (CG) was fed with a standard chow diet for 7 days. Group A1 and group A2 were fed with adenine supplemented chow diet for 7 days. At the end of the feeding period, after all groups was submitted intestinal obstruction. 99mTc-E. coli was injected into the rats’ terminal ileum under anesthetic. The rats were sacrificed under aseptic conditions at 24th h after the surgery. The uptake of 99mTc-E. coli was determined in organs such as the liver, mesenteric lymph nodes, spleen and ileum. Group A1 and group A2 results show that the uptake of 99mTc-E. coli decreased in the blood and organs comparing to the CG. As a result, it was observed that adenine reduced the level of BT when compared with CG. The beneficial effect of adenine on BT in intestinal obstruction was observed. However, further studies are needed to more clearly assess how this benefit can be achieved. 相似文献
32.
In this study, acrylamide-based hydrogels are synthesized by free radical solution polymerization in aqueous solution using ethylene glycol dimethacrylate (EGDMA) and its derivative polyethylene glycol dimethacrylate (PEGDMA) with different molecular weights as crosslinkers in the solution medium. The Fourier transform infrared spectroscopy technique is used for the structural characterization of the hydrogels. Dynamic swelling tests are conducted on acrylamide-based hydrogels for the determination of the swelling characteristics with respect to different crosslinking concentrations at room temperature. The parameters of swelling kinetics and diffusion mechanisms of the hydrogels are calculated with the aid of the data obtained. Accordingly, PEGDMA and EGDMA absorption capacity is found to increase with increasing concentrations. The lowest and highest water absorption capacities in PEGDMA810 and EGDMA crosslinked hydrogels are 22.73–48.39 and 10.15–16.02 g/g, respectively. Water intake of hydrogels crosslinked by EGDMA and PEGDMAs followed Fickian nature type diffusion except for PEGDM810, which has a swelling exponent greater than 0.5 and so does not follow a Fickian type of diffusion. PEGDM810 showed the fastest diffusion rate of between 5.87 × 10?4 and 10.87 × 10?4 cm2 s?1. 相似文献
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Keng Yoon Yeong Mohamed Ashraf Ali Chee Wei Ang Soo Choon Tan Hasnah Osman 《Tetrahedron letters》2014
A facile method to synthesize various 1,2-disubstituted benzimidazoles is developed. It is suggested that formation of a Meisenheimer adduct between the substrate, amine, and solvent aids the N-arylation process. The generality of the protocol is demonstrated by the efficient reactions involving numerous substituents ranging from electron-withdrawing groups to electron-donating groups. 相似文献
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Motivated by the high potential of shape memory alloys (SMA) in several industrial applications, we investigate the material response under cyclic loading. In particular, the focus is set on the modelling of functional fatigue, which results in the deterioration of the specific features of SMA. In fact, functional fatigue restricts SMA in terms of its applicability for real structures and workpieces. This necessitates the development of material models which take this phenomenon into account. (© 2015 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
36.
Prof. Dr. Samih A. Halawy Dr. Ahmed I. Osman Dr. Adel Abdelkader Mahmoud Nasr Prof. Dr. David W. Rooney 《ChemistryOpen》2022,11(3):e202200021
Measuring the Lewis-acidic surface sites in catalysis is problematic when the material‘s surface area is very low (SBET ≤1 m2 ⋅ g−1). For the first time, a quantitative assessment of total acidic surface sites of very small surface area catalysts (MoO3 as pure and mixed with 5–30 % CdO (wt/wt), as well as CdO for comparison) was performed using a smart new probe molecule, tetrahydrofuran (THF). The results were nearly identical compared to using another commonly used probe molecule, pyridine. This audition is based on the limited values of the surface area of these samples that likely require a relatively moderate basic molecule as THF with pKb=16.08, rather than strong basic molecules such as NH3 (pKb=4.75) or pyridine (pKb=8.77). We propose mechanisms for the interaction of vapour phase molecules of THF with the Lewis-cationic Mo and Cd atoms of these catalysts. Besides, dehydration of isopropyl alcohol was used as a probe reaction to investigate the catalytic activity of these catalysts to further support our findings in the case of THF in a temperature range of 175–300 °C. A good agreement between the obtained data of sample MoO3-10 % CdO, which is characterised by the highest surface area value, the population of Lewis-acidic sites and % selectivity of propylene at all the applied reaction temperatures was found. 相似文献
37.
Kok Tong Wong Hasnah Osman Thaigarajan Parumasivam Unang Supratman Mohammad Tasyriq Che Omar Mohamad Nurul Azmi 《Molecules (Basel, Switzerland)》2021,26(7)
A total of fourteen pyrazoline derivatives were synthesized through cyclo-condensation reactions by chalcone derivatives with different types of semicarbazide. These compounds were characterized by IR, 1D-NMR (1H, 13C and Distortionless Enhancement by Polarization Transfer - DEPT-135) and 2D-NMR (COSY, HSQC and HMBC) as well as mass spectroscopy analysis (HRMS). The synthesized compounds were tested for their antituberculosis activity against Mycobacterium tuberculosis H37Ra in vitro. Based on this activity, compound 4a showed the most potent inhibitory activity, with a minimum inhibitory concentration (MIC) value of 17 μM. In addition, six other synthesized compounds, 5a and 5c–5g, exhibited moderate activity, with MIC ranges between 60 μM to 140 μM. Compound 4a showed good bactericidal activity with a minimum bactericidal concentration (MBC) value of 34 μM against Mycobacterium tuberculosis H37Ra. Molecular docking studies for compound 4a on alpha-sterol demethylase was done to understand and explore ligand–receptor interactions, and to hypothesize potential refinements for the compound. 相似文献
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The kinetic and activation parameters for the rotation about the CC double bond and the C-N single bond in the compounds listed in Table 1 were determined by variable temperature NMR spectroscopy. Complete line shape analyses, using a computer REEP program, were carried out on several systems. The main objective of the present study is to determine the effect of the ring size in II on the two types of kinetic processes. 相似文献