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排序方式: 共有195条查询结果,搜索用时 15 毫秒
121.
Abstract Previous studies of cyanide exchange on square planar tetracyanoplatinate complex [Pt(CN)4]2- have been undertaken only at a high pH. For a more complete fundamental understanding of this system we extended the investigations of these exchanges over a large pH range. NMR kinetics methods (magnetisation transfer, isotopic exchange) proved to be very useful for obtaining quantitative rate data of the cyanide exchange on this complex. In fact it is quite significant that the reactivity of this metal center spans a ca. 9-order of magnitude range as a function of pH. Variable temperature and variable pressure studies were undertaken in aqueous solutions and the following activation parameters obtained: ΔH? = (25.1 ± 0.4) kJmol?1 and activation entropy ΔS? = -(142±2)JK?1mol?1 and activation volume ΔV? = -(27±2)cm3mol?1. 相似文献
122.
Poklis JL Amira D Wise LE Wiebelhaus JM Haggerty BJ Lichtman AH Poklis A 《Biomedical chromatography : BMC》2012,26(11):1393-1398
The disposition of the cannabimimetic naphthalen‐1‐yl‐(1‐pentylindol‐3‐yl)methanone (JWH‐018) in mice following inhalation of the smoke of the herbal incense product (HIP) ‘Buzz’ is presented. A high‐pressure liquid chromatography with electrospray ionization triple quadrupole mass spectrometer (HPLC/MS/MS) method was validated for the analysis of JWH‐018 in the specimens using deuterated Δ9‐tetrahydrocannabinol (d3‐THC) as the internal standard. JWH‐018 was isolated by cold acetonitrile liquid–liquid extraction. Chromatographic separation was performed on a Zorbaz eclipse XDB‐C18 column. The assay was linear from 1 to 1000 ng/mL. Six C57BL6 mice were sacrificed 20 min after exposure to the smoke of 200 mg ‘Buzz’ containing 5.4% JWH‐018. Specimen concentrations of JWH‐018 were: blood, 54–166 ng/mL (mean 82 ± 42 ng/mL); brain, 316–708 ng/g (mean 510 ± 166 ng/g); and liver, 1370–3220 ng/mL (mean 1990 ± 752 ng/mL). The mean blood to brain ratio for JWH‐018 was 6.8 and ranged from 4.2 to 10.9. After exposure, the responses of the mice were consistent with cannabinoid receptor type 1 activity: body temperatures dropped 7.3 ± 1.1 °C, and catalepsy, hyperreflexia, straub tail and ptosis were observed. The brain concentrations and physiological responses are consistent with the hypothesis that the behavioral effects of ‘Buzz’ are attributable to JWH‐018. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
123.
Amira Awadalla Mohamed R. Mahdi Mohamed H. Zahran Ahmed Abdelbaset-Ismail Mohamed El-Dosoky Amr Negm 《Molecules (Basel, Switzerland)》2022,27(7)
Cisplatin (CP) is a conventional chemotherapeutic agent with serious adverse effects. Its toxicity was linked to the stimulation of oxidative stress and inflammation. As a result, this study explored the protective effect of baicalein and alpha-tocopherol in nephrotoxicity induced by cisplatin. Until receiving an intraperitoneal injection of CP (3 mg/kg BW), rats were given baicalein orally 100 mg/kg for seven days or/and a single intraperitoneal injection of α-tocopherol 250 mg/kg. Renal function was tested to explore whether baicalein and α-tocopherol have any beneficial effects; blood urea nitrogen (BUN), serum creatinine, malondialdehyde (MDA) content, antioxidant activity biomarkers and histopathology of renal tissue, oxidative stress biomarkers, inflammatory response markers, and histopathological features of kidney architecture were measured. Cisplatin treatment resulted in extreme renal failure, as measured by high serum creatinine and BUN levels and severe renal changes. Cisplatin therapy resulted in increased lipid peroxidation and decreased glutathione and superoxide dismutase levels, reflecting oxidative stress. Upon treatment with α-tocopherol, baicalein, and combined therapy, there was augmentation in the antioxidant status as well as a reduction in IL-6, NF-κB, TNF, TLR2, and TLR4 and a significant increase in Keap-1 and NRF-2. The combined treatment was the most effective and the nearest to the normal status. These findings suggest that baicalein and α-tocopherol may be useful in preventing cisplatin-induced nephrotoxicity. 相似文献
124.
Synthesis of Some New Heterocycles Derived from Novel 2‐(1,3‐Dioxisoindolin‐2‐yl)Benzoyl Isothiocyanate
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Novel 2‐(1,3‐Dioxisoindolin‐2‐yl)benzoyl isothiocyanate was prepared and underwent addition–cyclization reactions with some nucleophilic reagents. Simultaneous or subsequent cyclization of the obtained adducts gave a diverse range of differently sized heterocycles and thioureas. The structures of the synthesized compounds were confirmed by microanalytical and spectral data. 相似文献
125.
Starting from 6-aryl-4-oxo-2-thioxo-1,2,3,4-tetrahydropyrimidine-5-carbonitrile (4a-d), a series of mono- and dialkyl derivatives 5a-j and 6a, b was synthesized. Hydrazinolysis of 4a, b, d and 5d afforded the hydrazino derivatives 7a-c which were cyclised to give the triazolopyrimidinones 8a-c and the pyrimidotriazinones 9a-c through the reaction with formic acid and chloroacetyl chloride, respectively. Most of the newly synthesized compounds were evaluated for their in-vitro antitumor activity. Compounds 6a and b displayed promising anticancer activity against leukaemia, non-small cell lung, melanoma, and renal cancer. On the other hand, all compounds prepared were screened for their in-vitro antibacterial and antifungal activities. Compounds 5h and j showed significant activity against Staphylococcus aureus, while compounds 5e, 7c and 8c displayed moderate inhibitory activity against Candida albicans. 相似文献
126.
Choucair A Soo PL Eisenberg A 《Langmuir : the ACS journal of surfaces and colloids》2005,21(20):9308-9313
Vesicles are spherical bilayers that offer a hydrophilic reservoir, suitable for the incorporation of water-soluble molecules, as well as a hydrophobic wall that protects the loaded molecules from the external solution. The permeability of a vesicle wall made from polystyrene can be enhanced by adding a plasticizer such as dioxane. Tuning the wall permeability allows loading and release of molecules from vesicles to be controlled. In this study, vesicles are prepared from polystyrene(310)-b-poly(acrylic acid)(36) and used as model carriers for doxorubicin (DXR), a weak amine and a widely used anticancer drug. To increase the wall permeability, different amounts of dioxane are added to the vesicle solution. A pH gradient is created across the vesicle wall (inside acidic) and used as an active loading method to concentrate the drug inside the vesicles. The results show that a pH gradient of ca. 3.8 units can enhance the loading level up to 10-fold relative to loading in the absence of the gradient. After loading, the release of DXR from vesicles is followed as a function of the wall permeability. The diffusion coefficient of doxorubicin through polystyrene (D) is evaluated from the initial slope of the release curves; the value of D ranges from 8 x 10(-17) to 6 x 10(-16) cm(2)/s, depending on the degree of plasticization of the vesicle wall. 相似文献
127.
Mohamad M.E. Shakdofa Hanan A. Mousa Ammar A. Labib Amira S. Abd‐El‐All Ahmed A. El‐Beih Mohamed M. Abdalla 《应用有机金属化学》2018,32(6)
A series of chromone Schiff base complexes were prepared and analytically as well as spectroscopically characterized. The ligand was found to act as a monobasic tridentate ligand bonded covalently or coordinatively to the metal ion via deprotonated hydroxyl group, azomethine nitrogen atom and carbonyl oxygen atom of antipyrine moiety. Both electronic spectra and magnetic measurements indicated an octahedral or a distorted octahedral geometry around the metal ions for all metal complexes except the nickel complex, which had a tetrahedral geometry. In addition, the ability of the newly prepared compounds to activate the tumour suppressor p53 in cancer cells was studied, with zinc and copper complexes showing promising activities for p53 ubiquitination compared with diphenylimidazole (reference drug). 相似文献
128.
Nihal F. F. Areed Amira El Fakharany Mohamed Farhat O. Hameed S. S. A. Obayya 《Optical and Quantum Electronics》2017,49(1):45
Two optical AND gates built in 2D photonic crystal (PhC) platform have been proposed and numerically simulated using 2D finite element method (FEM). The suggested logic gates consist of five PhC waveguides and silicon annular ring resonator filled by nematic liquid crystal (NLC) of type E7. The first proposed AND gate can handle two inputs and support two operating wavelengths, λ = 1.5 and 1.55 µm. However, the second proposed AND gate can handle three inputs at λ = 1.5 µm. The reported logic gates offer high and low transmission levels with a threshold of 0.5 and an ultra-high bit rate of not less than 0.3 Tbits/s. Further, the suggested AND gates operation can be switched off by using the NLC layer. 相似文献
129.
2-Cyanoacetohydrazide and 2-amino-4,5,6,7-tetrahydrobenzo[b]thiophene derivatives were exploited as starting materials for the syntheses of novel thienopyrimidines and triazolothienopyrimidines. The proclivity of these compounds toward one-carbon donor reagents such as carbon disulfide, phenyl isothiocyanate, and aromatic aldehydes was investigated. The structures of all synthesized compounds were ascertained by spectral and analytical data. The antimicrobial activity of the target synthesized compounds was tested against various microorganisms. 相似文献
130.
Hazem S. Elshafie Sadeek A. Sadeek Wael A. Zordok Amira A. Mohamed 《Molecules (Basel, Switzerland)》2021,26(5)
Recently, the design of new biological metal-ligand complexes has gained a special interest all over the world. In this research, new series of mixed ligand complexes from meloxicam (H2mel) and glycine (Gly) were synthesized. Structures of the compounds were investigated employing elemental analyses, infrared, electronic absorption, 1H NMR, thermal analyses, effective magnetic moment and conductivity. The estimated molar conductivity of the compounds in 1 × 10−3 M DMF solution indicates the non-electrolyte existence of the examined complexes. Additionally, the effective magnetic moment values refer to the complexes found as octahedral molecular geometry. The data of the infrared spectra showed the chelation of H2mel and Gly with metal ions from amide oxygen and nitrogen of the thyizol groups of H2mel and through nitrogen of the amide group and oxygen of the carboxylic group for Gly. Thermal analyses indicated that the new complexes have good thermal stability and initially lose hydration water molecules followed by coordinated water molecules, Gly and H2mel. The kinetic parameters were calculated graphically using Coats–Redfern and Horowitz–Metzeger methods at n = 1 and n ≠ 1. The density functional theory (DFT) calculations were performed at B3LYP levels. The optimized geometry of the ligand and its complexes were obtained based on the optimized structures. The data indicated that the complexes are soft with η value in the range 0.114 to 0.086, while η = 0.140 for free H2mel. The new prepared complexes were investigated as antibacterial and antifungal agents against some phyto- and human pathogens and the minimum inhibitory concentration (MIC) data showed that complex (A) has the lowest MIC for Listeria and E. coli (10.8 µg/mL). 相似文献