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排序方式: 共有289条查询结果,搜索用时 15 毫秒
61.
Raluca Maria Pop Ioana Corina Bocsan Anca Dana Buzoianu Veronica Sanda Chedea Sonia Ancua Socaci Michela Pecoraro Ada Popolo 《Molecules (Basel, Switzerland)》2020,25(22)
Natural products black cumin—Nigella sativa (N. sativa) and wild garlic—Allium ursinum (AU) are known for their potential role in reducing cardiovascular risk factors, including antracycline chemotherapy. Therefore, this study investigates the effect of N. sativa and AU water and methanolic extracts in a cellular model of doxorubicin (doxo)-induced cardiotoxicity. The extracts were characterized using Ultraviolet-visible (UV-VIS) spectroscopy, Fourier-transform infrared (FT-IR) spectroscopy, Liquid Chromatography coupled with Mass Spectrometry (LC-MS) and Gas Chromatography coupled with Mass Spectrometry (GC-MS) techniques. Antioxidant activity was evaluated on H9c2 cells. Cytosolic and mitochondrial reactive oxygen species (ROS) release was evaluated using 2′,7′-dichlorofluorescin-diacetate (DHCF-DA) and mitochondria-targeted superoxide indicator (MitoSOX red), respectively. Mitochondrial membrane depolarization was evaluated by flow cytometry. LC-MS analysis identified 12 and 10 phenolic compounds in NSS and AU extracts, respectively, with flavonols as predominant compounds. FT-IR analysis identified the presence of carbohydrates, amino acids and lipids in both plants. GC-MS identified the sulfur compounds in the AU water extract. N. sativa seeds (NSS) methanolic extract had the highest antioxidant activity reducing both intracellular and mitochondrial ROS release. All extracts (excepting AU methanolic extract) preserved H9c2 cells viability. None of the investigated plants affected the mitochondrial membrane depolarization. N. sativa and AU are important sources of bioactive compounds with increased antioxidant activities, requiring different extraction solvents to obtain the pharmacological effects. 相似文献
62.
Raluca Anamaria Şeptelean Amr A. A. Attia Alexandru Lupan R. Bruce King 《International journal of quantum chemistry》2019,119(9):e25880
The lowest energy structures for all of the eight-vertex [M]CB6H7 {[M] = CpFe, CpRu. Co(CO)2, Rh(CO)2, (Me3P)2Fe(H), (Me3P)2Ru(H)}, [M]C2B5H7 {[M] = CpMn, CpRe, Cr(CO)3, Mo(CO)3}, and [M]2C2B4H6 ([M] = CpFe, CpRu) systems having 16 skeletal electrons were found by density functional theory to be capped pentagonal bipyramids providing a degree 6 vertex for a metal atom. Thus the capped pentagonal bipyramid plays a similar role for eight-vertex metallaboranes with 16 skeletal electrons as the isocloso deltahedra play in 9- and 10-vertex metallaboranes with 18 and 20 skeletal electrons, respectively. Furthermore, in all of these metallaborane systems the closo bisdisphenoidal structures were always found to be higher energy structures than their capped pentagonal bipyramidal isomers. For the bimetallic systems Cp2M2C2B4H6 (M = Fe, Ru) even higher energy hexagonal bipyramid structures with degree 6 vertices for both metal atoms were also found. 相似文献
63.
64.
The theory of spatial localization for theJ heteronuclear rotating frame coherence transfer in the presence of the main magnetic field gradient is presented. The simplified case of an AX spin-1/2 pair in a liquid was considered. The two dimensional spatial profile for a cyclicJ heteronuclear rotating frame coherence transfer for1H and13C pair was evaluated and the applications to localized heteronuclear spectroscopy and imaging are discussed. 相似文献
65.
Raluca Ripan 《Fresenius' Journal of Analytical Chemistry》1943,125(1-2):38-40
Ohne Zusammenfassung 相似文献
66.
Raluca Nicoleta Darie Mihai Brebu Cornelia Vasile Marek Kozlowski 《Polymer Degradation and Stability》2003,80(3):551-566
Binary isotactic polypropylene (IPP)/polyamide 6 (PA6) and ternary IPP/PA6/ethylene–propylene diene terpolymer (EPDM) blends in various ratios were obtained in a Haake Rheocord mixer. Processing behaviour was changed in the presence of IPP functionalized with bismaleimide (BMI), maleic anhydride (MA) and acrylic acid (AA) as reactive compatibilizing agents. The thermal and thermo-oxidative behaviour of blends was studied by differential scanning calorimetry and thermogravimetry. The functionalized IPPs modify the crystallinity degree and the decomposition behaviour of both IPP and PA6 as a result of chemical reactions of functional groups with those of the PA6. The changes depend on the IPP/PA6 or IPP/PA6/EPDM ratio, the chemical nature and amount of the functionalized IPP. On the basis of the processing and thermal data one can conclude that the compatibilizing agent effect increases in the following order: IPP-AA 相似文献
67.
Spectrophotometric determination of magnesium in pharmaceutical preparations by cost-effective sequential injection analysis 总被引:1,自引:0,他引:1
A simple and rapid, inexpensive spectrophotometric method was proposed for magnesium assay in pharmaceutical preparations by sequential injection analysis (SIA). The method is based on the reaction between o-cresolphthalein complexone (CPC) and Mg(II) in alkaline media, yielding a pink colored complex with absorption maximum at 570 nm. Since the formation constant between Ca-CPC and Mg-CPC is similar, initially a sample/standard solution was aspirated into the holding coil followed by a mixture of masking-buffer solutions. This was done because masking of calcium should be accomplished before Mg-CPC complexation. Then the reagent was introduced into the reaction coil to produce a colored complex, which is measured spectrophotometrically at 570 nm. In this way the interference of calcium was reduced. Furthermore, all the parameters that affect the reaction were evaluated. The calibration curve is linear over a range of 0-20 mg l−1 of Mg(II) with a detection limit of 0.24 mg l−1. A sample throughput of 80 samples per hour and relative standard deviation <2.0% were achieved. The proposed method was successfully applied for the assay of magnesium in three different compositions of pharmaceutical preparations (tablets). The results were found to be in good agreement with the manual flame atomic absorption spectrophotometry (FAAS) and UV-Vis spectrophotometry methods and with the claimed values by the manufactures. The t-test shows no significant difference at 95% confidence level. 相似文献
68.
69.
Maria Elena Grad Georgeta Maria Simu Simona Gabriela Muntean Gheorghe Ilia 《Journal of the Iranian Chemical Society》2013,10(4):807-816
The synthesis of six new symmetrical disazo direct dyes containing 4,4′-diaminostilbene-2,2′-disulphonic acid as middle component and N-(2-chlorophenyl)-2-hydroxybenzamide, N-(3-chlorophenyl)-2-hydroxybenzamide, N-(4-chlorophenyl)-2-hydroxybenzamide, N-(2-bromophenyl)-2-hydroxybenzamide, N-(3-bromophenyl)-2-hydroxybenzamide, N-(4-bromophenyl)-2-hydroxybenzamide as coupling components is presented. The synthesized dyes were analyzed by thin layer chromatography, electronic spectra and HPLC technique. Their structures were elucidated by FT/IR and 13C-NMR spectroscopy. The CIELAB (1976) colour space was used in all the colour measurements for the six disazo stilbene dyes under the CIE recommended illuminants: D65 (natural day light), A (tungsten light), F2 (fluorescent light) and the standard 10° observer, respectively. The colour differences: ΔEab* and ΔECMC were calculated against one standard. The results reveal a good colouring power of the new azo-stilbene dyes. 相似文献
70.
Catalina Cioates Negut Raluca‐Ioana Stefan‐van Staden Florian Harja Jacobus Frederick van Staden 《Electroanalysis》2020,32(1):7-10
New synthesized fatty acid amides (N‐(2‐(piperidin‐1‐yl)ethyl)oleamide, and N‐(2‐(pyrrolidin‐1‐yl)ethyl)oleamide) were used for the design of stochastic sensors based on nanographene paste. The stochastic sensors were used for pattern recognition of four amino acids: L‐histidine, L‐tyrosine, L‐ornithine, and L‐lysine in wines. The pattern recognition was performed based on the signatures recorded for each of the amino acids. The limits of determination allow the assay of amino acids in wine at very low concentrations faster, reliable, and more cost effective than other methods proposed to date. 相似文献