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排序方式: 共有124条查询结果,搜索用时 15 毫秒
41.
S. Kashani A. A. Ranjbar M. M. Madani M. Mastiani H. Jalaly 《Journal of Applied Mechanics and Technical Physics》2013,54(5):702-712
The effects of nanoparticle dispersion on solidification of a Cu-n-hexadecane nanofluid inside a vertical enclosure are investigated numerically for different temperatures of the left vertical wall. An enthalpy porosity technique is used to trace the solid-liquid interface. The resulting nanoparticle-enhanced phase change materials (NEPCMs) exhibit enhanced thermal conductivity in comparison to the base material. The effect of the wall temperature and nanoparticle volume fraction are studied in terms of the solid fraction and the shape of the solid-liquid phase front. It has been found that a lower wall temperature and a higher nanoparticle volume fraction result in a larger solid fraction. The increase in the heat release rate of the NEPCM shows its great potential for diverse thermal energy storage applications. 相似文献
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Wedad S. Sarawi Ahlam M. Alhusaini Laila M. Fadda Hatun A. Alomar Awatif B. Albaker Amjad S. Aljrboa Areej M. Alotaibi Iman H. Hasan Ayman M. Mahmoud 《Molecules (Basel, Switzerland)》2021,26(18)
Copper (Cu) is essential for multiple biochemical processes, and copper sulphate (CuSO4) is a pesticide used for repelling pests. Accidental or intentional intoxication can induce multiorgan toxicity and could be fatal. Curcumin (CUR) is a potent antioxidant, but its poor systemic bioavailability is the main drawback in its therapeutic uses. This study investigated the protective effect of CUR and N-CUR on CuSO4-induced cerebral oxidative stress, inflammation, and apoptosis in rats, pointing to the possible involvement of Akt/GSK-3β. Rats received 100 mg/kg CuSO4 and were concurrently treated with CUR or N-CUR for 7 days. Cu-administered rats exhibited a remarkable increase in cerebral malondialdehyde (MDA), NF-κB p65, TNF-α, and IL-6 associated with decreased GSH, SOD, and catalase. Cu provoked DNA fragmentation, upregulated BAX, caspase-3, and p53, and decreased BCL-2 in the brain of rats. N-CUR and CUR ameliorated MDA, NF-κB p65, and pro-inflammatory cytokines, downregulated pro-apoptotic genes, upregulated BCL-2, and enhanced antioxidants and DNA integrity. In addition, both N-CUR and CUR increased AKT Ser473 and GSK-3β Ser9 phosphorylation in the brain of Cu-administered rats. In conclusion, N-CUR and CUR prevent Cu neurotoxicity by attenuating oxidative injury, inflammatory response, and apoptosis and upregulating AKT/GSK-3β signaling. The neuroprotective effect of N-CUR was more potent than CUR. 相似文献
43.
Nadia Naim Marie-Laure Fauconnier Nabil Ennahli Abdessalem Tahiri Mohammed Baala Ilham Madani Said Ennahli Rachid Lahlali 《Molecules (Basel, Switzerland)》2022,27(24)
Numerous fungal plant pathogens can infect fresh fruits and vegetables during transit and storage conditions. The resulting infections were mainly controlled by synthetic fungicides, but their application has many drawbacks associated with the threatened environment and human health. Therefore, the use of natural plants with antimicrobial potential could be a promising alternative to overcome the side effects of fungicides. In this regard, this study aimed at evaluating the antifungal activity potential of saffron petal extract (SPE) against three mains important fungal pathogens: Rhizopus stolonifer, Penicillium digitatum and Botritys cinerea, which cause rot decay on the tomato, orange and apple fruits, respectively. In addition, the organic composition of SPE was characterized by attenuated total reflection Fourier transform infrared (ATR-FT-IR) spectroscopy and its biochemical, and gas chromatography-mass spectrometry (GC-MS) analyses were carried out. The obtained results highlighted an increased inhibition rate of the mycelial growth and spore germination of the three pathogenic fungi with increasing SPE concentrations. The mycelial growth and spore germination were completely inhibited at 10% of the SPE for Rhizopus stolonifer and Penicillium digitatum and at 5% for B. cinerea. Interestingly, the in vivo test showed the complete suppression of Rhizopus rot by the SPE at 10%, and a significant reduction of the severity of grey mold disease (37.19%) and green mold, when applied at 5 and 10%, respectively. The FT-IR spectra showed characteristic peaks and a variety of functional groups, which confirmed that SPE contains phenolic and flavonoid components. In addition, The average value of the total phenolic content, flavonoid content and half-maximal inhibitory concentration (IC50) were 3.09 ± 0.012 mg GAE/g DW, 0.92 ± 0.004 mg QE/g DW and 235.15 ± 2.12 µg/mL, respectively. A volatile analysis showed that the most dominant component in the saffron petal is 2(5H)-Furanone (92.10%). Taken together, it was concluded that SPE could be used as an alternative to antioxidant and antifungal compounds for the control of postharvest diseases in fruits. 相似文献
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45.
C. Madani E. M. Chambaz M. Rigaud P. Chebroux J. C. Breton F. Berthou 《Chromatographia》1977,10(8):466-472
Summary A new procedure for the preparation of high resolution open tubular glass capillary columns is described. This procedure involves the preparation of polysiloxane polymers obtained by alkaline hydrolysis of alkyl chlorosilane. The mixture of polysiloxane polymers is then coated on the wall of previously HCl treated glass capillary columns using a dynamic method. A base-catalysed reaction using gaseous ammonia, applied to the coated polymers leads to a stable chemically bonded stationary phase, with non-polar characteristics. This type of column is easier to prepare than conventional ones and exhibits excellent chromatographic properties, both with regard to their resolution, stability and reproducibility. The flexibility of this method permits the use of other types of commercially available chlorosilanes (i.e. methylphenyl chlorosilane) to prepare polar polysiloxane polymers suitable for analysis of complex biochemical mixtures, such as steroid metabolites. 相似文献
46.
Jacques Brocard Jacques Lebibi Lydie Pelinski Madani Mahmoudi 《Tetrahedron letters》1986,27(52):6325-6328
Reaction of ortho alkyl or alkoxy phenyl carbinol with Cr(CO)6 affords arene chromium tricarbonyl complexes with 38 to 86% of diastereoisomeric excess. The behavior of the two diastereoisomers shows a striking difference. Equimolar mixture of (RR,SS) and (RS,SR) diastereoisomers treated with concentrated sulfuric acid and methanol gives (RS,SR) ether while (RR,SS) alcool remains unchanged. 相似文献
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Alireza Pourhossein Masoud Madani Mohsen Shahlaei Kambiz Fakhri Parisa Alimohamadi Maryam Amiri 《Central European Journal of Chemistry》2009,7(3):382-387
A sensitive, simple and rapid method for ultra-trace determination of iron and manganese based on ultrasound assisted pseudodigestion
in citric acid fermentation medium samples (beet and cane molasses and raw sugar based mediums) is described. Parameters influencing
pseudo-digestion, such as sonication time, sample mass and solvent system were fully optimized. Final solutions obtained upon
sonication were analyzed by electrothermal atomic absorption spectrometry (ETAAS). The best conditions for metal pseudo-digestion
were as follows: a 25, 30 and 20 min sonication time for beet molasses, cane molasses and raw sugar based medium samples,
respectively, 0.7 g sample mass of raw sugar based samples, 0.5 g sample mass of molasses based samples and an extraction
mixture of concentrated HNO3-H2O2, in 25 mL of solvent. Analytical results obtained for the two metals by ultrasound assisted pseudo-digestion and conventional
wet digestion methods showed a good agreement. This method reduces the time required for all treatments (heating to dryness,
cooling and separation) in comparison with conventional wet digestion method. The accuracy of the method was tested by comparing
the obtained results with that of conventional wet digestion method.
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