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1.
Beevers AP Fettes KJ Sabbagh G Murad FK Arnold JR Cosstick R Fisher J 《Organic & biomolecular chemistry》2004,2(1):114-119
High-resolution NMR spectroscopy has been used to establish the conformational consequences of the introduction of a single 3[prime or minute]-S-phosphorothiolate link in the DNA strand of a DNA : RNA hybrid. These systems are of interest as potential antisense therapeutic agents. Previous studies on similarly modified dinucleotides have shown that the conformation of the sugar to which the sulfur is attached shifts to the north (C(3[prime or minute])-endo/C(2[prime or minute])-exo). Comparisons made between NOESY cross-peak intensities, and coupling constants from PE-COSY spectra, for both non-modified and modified duplexes confirm that this conformational shift is also present in the double helical oligonucleotide system. In addition it is noted that in both the dinucleotides and the modified duplex, the conformation of the sugar ring 3[prime or minute] to the site of modification is also shifted to the north. That this pattern is observed in the small monomeric system as well as the larger double helix is suggestive of some pre-ordering of the sequences. The conclusion is supported by consideration of the (1)H chemical shifts of the heterocyclic bases near the site of the modification. The enhanced stability that these conformational changes should bring was confirmed by UV thermal melting studies. Subsequently a series of singly and doubly 3[prime or minute]-S-phosphorothiolate-modified duplexes were investigated by UV. The results are indicative of an additive effect of the modification with thermodynamic benefit being derived from alternate spacing of two modified linkers. 相似文献
2.
Abdulmajeed A. AbuDujayn Abdellatif A. Mohamed Mohamed Saleh Alamri Shahzad Hussain Mohamed A. Ibraheem Akram A. Abdo Qasem Ghalia Shamlan Nashi K. Alqahtani 《Molecules (Basel, Switzerland)》2023,28(1)
The effectiveness of hydrocolloids (2% maximum in various combinations) from various sources, including maltodextrins (MD) with polymerization degree (DP) 18 and ziziphus gum (ZG), on the dough properties and quality of panned bread, as well as the possibility of using them to delay the bread staling process, have been investigated after 24, 72, and 96 h of storage. By evaluating the pasting capabilities of wheat flour slurry, dough properties, and the final product, the effects of the ziziphus gum (ZG) and maltodextrins (MD) were ascertained. A TA-TXT texture analyzer, a texture profile analysis test, and Micro-doughLab were used to evaluate the dough mixing properties. Additionally, a hedonic sensory evaluation of the overall acceptance of the bread, as well as its texture, aroma, taste, and color, was done. It is clear that MD had a more distinct impact than ZG on the way dough was mixed, the texture of the gel, and the finished product. The combination of MD and ZG significantly altered the bread’s physical characteristics and its aging over time. The decreased peak viscosity and noticeably smaller setback of wheat flour gels, which corresponded to lower gel hardness, serve as evidence of reduced amylose retrogradation. At 2%, MD outperformed ZG in terms of increasing water absorption, dough stability, and bread loaf volume. With the exception of the blend that included three times as much MD as ZG, all mixes, including the control, exhibited an increase in bread firmness as a function of time after storage. Overall, the panelists liked (score of 5 and above) the bread made with mixes that had either MD or ZG, or a combination of both. 相似文献
3.
Pandurangan Subash-Babu Hussah Mohammed Alowaidh Laila Naif Al-Harbi Ghalia Shamlan Amal A. Aloud Sahar Abdulaziz AlSedairy Ali Abdullah Alshatwi 《Molecules (Basel, Switzerland)》2022,27(4)
Excessive storage of lipids in visceral or ectopic sites stimulates adipokine production, which attracts macrophages. This process determines the pro- and anti-inflammatory response regulation in adipose tissue during obesity-associated systemic inflammation. The present study aimed to identify the composition of Ocimum basilicum L. (basil) seed extract and to determine its bio-efficacy on adipocyte thermogenesis or fatty acid oxidation and inhibition of lipid accumulation and adipokine secretion. Ocimum basilicum L. seed methanol extract (BSME) was utilized to analyze the cytotoxicity vs. control; lipid accumulation assay (oil red O and Nile red staining), adipogenesis and mitochondrial-thermogenesis-related gene expression vs. vehicle control were analyzed by PCR assay. In addition, vehicle control and BSME-treated adipocytes condition media were collected and treated with lipopolysaccharide (LPS)-induced macrophage to identify the macrophage polarization. The results shown that the active components present in BSME did not produce significant cytotoxicity in preadipocytes or macrophages in the MTT assay. Furthermore, oil red O and Nile red staining assay confirmed that 80 and 160 μg/dL concentrations of BSME effectively arrested lipid accumulation and inhibited adipocyte maturation, when compared with tea polyphenols. Gene expression level of adipocyte hyperplasia (CEBPα, PPARγ) and lipogenesis (LPL)-related genes have been significantly (p ≤ 0.05) downregulated, and mitochondrial-thermogenesis-associated genes (PPARγc1α, UCP-1, prdm16) have been significantly (p ≤ 0.001) upregulated. The BSME-treated, maturing, adipocyte-secreted proteins were detected with a decreased protein level of leptin, TNF-α, IL-6 and STAT-6, which are associated with insulin resistance and macrophage recruitment. The “LPS-stimulated macrophage” treated with “BSME-treated adipocytes condition media”, shown with significant (p ≤ 0.001) decrease in metabolic-inflammation-related proteins—such as PGE-2, MCP-1, TNF-α and NF-κB—were majorly associated with the development of foam cell formation and progression of atherosclerotic lesion. The present findings concluded that the availability of active principles in basil seed effectively inhibit adipocyte hypertrophy, macrophage polarization, and the inflammation associated with insulin resistance and thrombosis development. Ocimum basilicum L. seed may be useful as a dietary supplement to enhance fatty acid oxidation, which aids in overcoming metabolic complications. 相似文献
4.
Oksana Desiatkina Martin Msching Nicoleta Anghel Ghalia Boubaker Yosra Amdouni Andrew Hemphill Julien Furrer Emilia Punescu 《Molecules (Basel, Switzerland)》2022,27(23)
Aiming toward compounds with improved anti-Toxoplasma activity by exploiting the parasite auxotrophies, a library of nucleobase-tethered trithiolato-bridged dinuclear ruthenium(II)-arene conjugates was synthesized and evaluated. Structural features such as the type of nucleobase and linking unit were progressively modified. For comparison, diruthenium hybrids with other type of molecules were also synthesized and assessed. A total of 37 compounds (diruthenium conjugates and intermediates) were evaluated in a primary screening for in vitro activity against transgenic Toxoplasma gondii tachyzoites constitutively expressing β-galactosidase (T. gondii β-gal) at 0.1 and 1 µM. In parallel, the cytotoxicity in non-infected host cells (human foreskin fibroblasts, HFF) was determined by alamarBlue assay. Twenty compounds strongly impairing parasite proliferation with little effect on HFF viability were subjected to T. gondii β-gal half maximal inhibitory concentration determination (IC50) and their toxicity for HFF was assessed at 2.5 µM. Two promising compounds were identified: 14, ester conjugate with 9-(2-oxyethyl)adenine, and 36, a click conjugate bearing a 2-(4-(hydroxymethyl)-1H-1,2,3-triazol-1-yl)methyl substituent, with IC50 values of 0.059 and 0.111 µM respectively, significantly lower compared to pyrimethamine standard (IC50 = 0.326 µM). Both 14 and 36 exhibited low toxicity against HFF when applied at 2.5 µM and are candidates for potential treatment options in a suitable in vivo model. 相似文献
5.
Novel thiocyanate-selective membrane sensors based on di-, tetra-, and hexa-imidepyridine ionophores
Potentiometric thiocyanate-selective sensors based on the use of three synthesized di-, tetra-, and hexa-imidepyridine derivatives as novel anionic neutral ionophores in plasticized poly(vinyl chloride) (PVC) membranes are described. The sensors exhibit significantly enhanced response towards thiocyanate ions over the concentration range 5×10−6 to 1.0×10−2 M with a lower detection limit of 0.3 μg ml−1 and slopes ranging from −55.6 to −58.3 mV per decade. Fast and stable response, good reproducibility, long-term stability, applicability over a wide pH range (2-8) and high selectivity for SCN− ion in the presence of 18 common anions are demonstrated. The sensors are used for direct potentiometric measurements of thiocyanate ions over the concentration range 0.2-580 μg ml−1 and for monitoring sequential titration of some metal ions (e.g. Ag+, Tl+, Cu2+, Pb2+) in binary and ternary mixtures. Sequential binding of these metal ions with SCN− ensures share stepwise titration curves with consecutive end point breaks at the equivalent points. Recoveries of 98.5-99.1±0.3% are obtained for metal ion concentrations of 0.06-4 mg ml−1. 相似文献
6.
Multi-walled carbon nanotubes (MWCNTs) were used successfully for the removal of heavy metals from aqueous solution. Characterization techniques showed the carbon as nanotubes with an average diameter between 40 and 60 nm and a specific surface area of 61.5 m2 g?1. The effect of carbon nanotubes mass, contact time, metal ions concentration, solution pH, and ionic strength on the adsorption of Cu(II), Pb(II), Cd(II) and Zn(II) by MWCNTs were studied and optimized. The adsorption of the heavy metals from aqueous solution by MWCNTs was studied kinetically using different kinetic models. A pseudo-second order model and the Elovich model were found to be in good agreement with the experimental data. The mechanism of adsorption was studied by the intra-particle diffusion model, and the results showed that intra-particle diffusion was not the slowest of the rate processes that determined the overall order. This model also revealed that the interaction of the metal ions with the MWCNTs surface might have been the most significant rate process. There was a competition among the metal ions for binding of the active sites present on the MWCNTs surface with affinity in the following order: Cu(II) > Zn(II) > Pb(II) > Cd(II). 相似文献
7.
Mabrouk Bouabdallah Ghalia Baguenane-Benalia Amar Saadi Hicham Cheniti Jean-Claude Gachon Etienne Patoor 《Journal of Thermal Analysis and Calorimetry》2013,112(1):279-283
The shape memory alloys based on the ternary system Cu–Al–Ni are able to produce a memory effect at high temperatures. However, if the material undergoes an accidental overheating, a transformation process leads to progressive loss of its characteristics. In this study, the effect of ageing on the metastable β1 (austenite) phase of a Cu–13.3 %Al–4 %Ni shape memory alloy was investigated. In addition, the effects of heating rate between 450 and 580 °C on the structural transformations of austenite after cooling to room temperature were studied. Observation by transmission electron microscopy of the structure that has undergone an isothermal ageing shows that the precipitation process depends on the maximum ageing temperature. Furthermore, calorimetric analysis shows that precipitates dissolution is possible when rapid heating between 450 and 580 °C. This behaviour is observed on the cooling diagram which shows a martensitic transformation. 相似文献
8.
Ghalia Boukellal Audrey Durin Rudy Valette Jean-Fran?ois Agassant 《Rheologica Acta》2011,50(5-6):547-557
The predictions of the Marrucci and Ianniruberto model (2003) have been studied in various rheometric flows as well as a planar elongation flow using the ??optical elongational rheometer?? technique proposed by Schuberth and Münstedt (Rheol Acta 47:111?C119, 2008). This combination of techniques extended the range of pertinence of the model to high-extensional rates. Relevance of the identified parameters with respect to tube theory was then discussed. 相似文献
9.
New membrane sensors with cylindrical configuration for lead (II) ions are described based on the use of three newly synthesized pyridine carboximide derivatives as neutral ionophores in plasticized PVC membranes. The sensors exhibit significantly enhanced response towards lead (II) ions over the concentration range 4×10−6-1×10−2 mol l−1 at pH 4.5-7 with a lower detection limit of 0.4-3.7 μg ml−1. The sensors display near-Nernstian slope of 26.0-33.1 mV per decade for Pb(II) ions. Effects of plasticizers, lipophilic salts and various foreign common ions are tested. The sensors show long life span, good selectivity for Pb(II) over a wide variety of other metal ions, long term stability, high reproducibility, and fast response. Validation of the method by measuring the lower detection limit, range, accuracy, precision, repeatability and between-day-variability reveals good performance characteristics of the proposed sensors. The sensors are used for direct determination of lead in stack emissions of lead smelters, assay of lead in rocks and monitoring of potentiometric titration of Pb(II) with EDTA. The results obtained agree fairly well with data obtained by atomic absorption spectrometry. 相似文献
10.
Abdellatif A. Mohamed Mohamed Saleh Alamri Shahzad Hussain Mohamed A. Ibraheem Akram A. Abdo Qasem Ghalia Shamlan Ibrahim A. Ababtain 《Molecules (Basel, Switzerland)》2022,27(10)
The influence of 2% and 5% Cordia (CG) and Ziziphus (ZG) gums on dough characteristics and cookie quality was investigated. Micro-DoughLab, a texture analyzer (TA), a rapid viscoanalyzer (RVA), and solvent retention capacity were used to examine the effect of CG and ZG gums on dough physicochemical parameters (SRC) and cookie quality. The diameter, thickness, spread, and sensory evaluation of cookies were evaluated. With the addition of CG and ZG, dough softness, mixing time, and mixing tolerance index (MTI) increased, whereas stability and water absorption decreased. TA data showed that adding gums resulted in softer and less sticky doughs than the control, whereas RVA data showed that adding CG resulted in a significant increase in peak viscosity, but no change in flour gel setback. In comparison to the control and CG samples, the ZG samples exhibited the most dough extensibility. The thickness and diameter of the cookies increased but the spread decreased, due to the added gums. The gum-containing cookies had a lower overall acceptability by panelists than the control, although only by a small margin. Gum-containing cookies, on the other hand, can deliver up to 5% soluble fiber. 相似文献