排序方式: 共有23条查询结果,搜索用时 46 毫秒
1.
2.
Abdelwahab SI Zaman FQ Mariod AA Yaacob M Abdelmageed AH Khamis S 《Journal of the science of food and agriculture》2010,90(15):2682-2688
BACKGROUND: Plant essential oils are widely used as fragrances and flavours. Therefore, the essential oils from the leaves of Cinnamomum pubescens Kochummen (CP) and the whole plant of Etlingera elatior (EE) were investigated for their antioxidant, antibacterial and phytochemical properties. RESULTS: CP and EE were found to contain appreciable levels of total phenolic contents (50.6 and 33.41 g kg?1 as gallic acid equivalent) and total flavonoid contents (205.6 and 244.8 g kg?1 as rutin equivalent), respectively. DPPH free radical scavenging activity of CP is superior to EE (P < 0.05) showing IC50 of 77.2 and 995.1 µg mL?1, respectively. Methicillin‐resistant Staphylococcus aureus (MRSA), Bacillus subtilis, Pseudomonas aeruginosa and Salmonella choleraesuis were tested against CP and EE. Only MRSA was the most susceptible bacteria to CP. GC/MS studies resulted in the identification of 79 and 73 compounds in CP and EE, respectively. The most abundant components of EE included β‐pinene (24.92%) and 1‐dodecene (24.31%). While the major compound in CP were 1,6‐octadien‐3‐ol,3,7‐dimethyl (11.55%), cinnamaldehyde (56.15%) and 1‐phenyl‐propane‐2,2‐diol diethanoate (11.38%). CONCLUSION: This study suggests that the essential oils from Cinnamomum pubescens Kochummen and Etlingera elatior could be potentially used as a new source of natural antioxidant and antibacterial in the food and pharmaceutical industries. Copyright © 2010 Society of Chemical Industry 相似文献
3.
Salga MS Ali HM Abdulla MA Abdelwahab SI 《International journal of molecular sciences》2012,13(2):1393-1404
The current study described the synthesis and the in vivo acute oral toxicity evaluations in Sprague Dawley rats. The compounds were characterized by elemental analyses, LC-MS, FTIR, (1)H NMR, (13)C NMR and UV-visible spectroscopy. In the acute toxicity study, a single administration of the compounds was performed orally to the rats at the single doses of 2000 mg/kg and they were then monitored for possible side effects, mortality or behavioral changes up to 14 days. The serum level of aspartate (AST), alanine aminotransferases (ALT), alkaline phosphate (ALP), triglyceride, high density lipoprotein (HDL), immunoglobulins (GAM) and the C-reactive proteins did not significantly change. The hematological indices white blood cells (WBC), haematocrit (HCT), red blood cells (RBC), mean corpuscular volume (MCV), mean corpuscular haemoglobin concentration (MCHC), and mean corpuscular hemoglobin (MCH) were within the normal range. The renal function indices examined were also within the reference range. Generally, the compounds exhibited low toxic effects as required for further in vivo therapeutic studies. 相似文献
4.
5.
Inverse microemulsion system of cetyltrimethylammonium bromide (CTAB) molecules is utilized for virtually monodispersed and controlled growth of HC1 polyaniline (PANI) nanoparticles at room temperature (ca. 300 K). The templated electroconductive polymer reveals lamellar crystalline structure under X-ray diffraction signifying marked sub-chain alignment of the polymcrized nanoparticles. The nanostructured polymer has spherically symmetric morphology in a size range of 2.0 nm to 6.0 nm under electron microscope examination. Gel permeation chromatography gives polydispersity index of 1.02 for nanostructured polymer in agreement with the size monodispersity transpired by electron microscopy. The d.c. electrical conductivity σdc of PANI at room temperature is 10.11 S/cm whereas the variation of conductivity with temperature in the range 227-303 K reveals that the conducting mechanism can be considered as three-dimensional ariable-range-hopping (3D-VRH). UV-Vis spectrum indicates two broad absorption bands due to polaron formation that contributes to enhanced electrical conductivity of the polymer. The fundamental bsorption edge in the polymer is formed by direct allowed transitions to the extent that the optical band gap value was found to be 2.35 eV. The crystalline nanostructure and homogeneous doping attained in the cationic template of amphiphile are argued as ontributing factors to the enhanced conductivity of the polymer. 相似文献
6.
Over 1500 authentic and commercial A. senegal var. senegal gum samples were analysed to evaluate existing quality control parameters and to assess the potential of new parameters such as pH, viscosity, viscosity average molecular weight (MV) equivalent weight and total uronic acid content as additional qualifying indices. The data obtained indicate the following mean values: moisture (10.75%), ash (3.77%), nitrogen (0.328%), specific rotation (−31.3°), pH (4.66), equivalent weight (1436) and total uronic acid content (13.71%). The results also indicate wide variations in intrinsic viscosity and viscosity average molecular weight (mean values 16.4 ml g−1 and 9.0×105, respectively. Accordingly these parameters, therefore, cannot be recommended as qualifying indices. 相似文献
7.
Norbaiti Mohd Isa Ahmad Bustamam Abdul Siddig Ibrahim Abdelwahab Rasedee Abdullah Mohd Aspollah Sukari Behnam Kamalidehghan A. Hamid A. Hadi Syam Mohan 《Journal of Functional Foods》2013,5(1):87-97
The anti-cancer effect of Boesenbergin A (BA) isolated from Boesenbergia rotunda, via the induction of apoptosis resulting from mitochondrial dysfunction was assessed in human non-small cell lung cancer (A549) cells. The apoptotic mechanisms of BA induction on cancer cells were studied in the present study for the first time. Nuclear stain, measuring the accumulation of sub-G1 cell population and DNA ladder were done to determine the apoptosis. Further investigations into the depletion of mitochondrial membrane potential and release of cytochrome c determined that BA treatment induced apoptosis via the regulation of the expression of pro-survival and pro-apoptotic Bcl-2 family members. The involvement of both intrinsic and extrinsic caspases (caspase 3/7, 9 and 8) were significantly increased. Moreover the role of free radicals was significantly found to be elevated with concomitant decrease in HSP70. In conclusion the results from the current study indicated BA could be a promising agent for the treatment of lung cancer. 相似文献
8.
Modelling Sectorally Differentiated Water Prices - Water Preservation and Welfare Gains Through Price Reform? 总被引:1,自引:0,他引:1
Jonas Luckmann Dorothee Flaig Harald Grethe Khalid Siddig 《Water Resources Management》2016,30(7):2327-2342
This study simulates the economy-wide effects of introducing new water pricing systems in Israel. A Computable General Equilibrium (CGE) model, STAGE_W, is used that includes multiple water commodities produced from different water resources. The current water pricing scheme supplies potable water to municipalities at fees above the supply costs and subsidizes water delivered to the agricultural and the manufacturing sectors. Due to limited freshwater resources, climate change and population growth, water scarcity is an increasing problem in Israel. Therefore, pricing systems which lead to a more efficient allocation of water are intensely debated. This study analyzes two alternative pricing schemes under discussion in Israel: price liberalization, which unifies the prices for all potable water consumers at cost recovery rates, and marginal pricing that lifts the potable water price to the cost of desalination. Both schemes reduce water demand with limited economic costs. Price liberalization is the more favourable option from a national welfare perspective, while marginal pricing allows for larger water savings and, in the long run, independence from fresh water resources. 相似文献
9.
Chemical looping reforming (CLR) is a recent trend for syngas production,which has several merits compared to the conventional manner.One of the most important issues for CLR is to find low-cost mate-rial as oxygen carriers,so iron is a promising candidate.This paper contributes to testing the thermody-namic ability of iron-based oxygen carrier for chemical looping reforming of ethanol (CLRE).Iron thermodynamically investigated in temperature 100-1300 ℃ and excess oxygen number (Φ) 0-4.It was found that the temperature and Φ have an apparent effect on the gaseous composition produced from the process.Increases in temperature within the range of 100-1300 ℃ enhanced syngas generated and reduced coke formation and CH4.Whereas,increased Φ,particularly at higher temperatures,had also enhanced syngas production as well as reduced coke formation.However,increasing Φ for values beyond one had decreased syngas and not significantly reduced coke deposition.Moreover,an experimental investigation was carried out in a fixed bed reactor for more in-depth verification of iron ability as an oxy-gen carrier through using magnetite ore (mainly Fe3O4).It found that the effect of temperature on syngas production was consistent with that calculated thermodynamically,as syngas increased with raising the temperature through the CLRE. 相似文献
10.
The economic, social, ecological and environmental roles and benefits of forests are obvious and need no emphasis. Inefficient use of fuel wood is considered one of the important causes of deforestation. Use of more efficient improved cookstoves is proposed as one of the measures that can reduce demand for fuel wood and charcoal and help in lowering the annoying deforestation rate in many developing countries. During the 1980s and 1990s several programs aiming at testing and disseminating energy saving technologies were implemented in Sudan. One of these technologies was improved cookstoves, which was intended to increase the efficiency of using energy from biomass sources. This study is carried out to examine the adoption rate and the factors affecting adoption of improved cookstoves in Khartoum State. The study is based on primary data collected through personal interviews with husbands and wives in 300 randomly selected households. Regression analysis was used to analyze the data. The results showed that the device's adoption rate was very low. The improved cookstove's relative advantage, housewife's exposure to messages about improved cookstoves, educational level of the housewife and the average educational level of the female household's members had significant positive effect on the household's innovativeness regarding adoption of improved cookstove. Wife's age and the educational level of the husband had negative significant effects. In the Sudanese patriarchal society all the household domestic tasks, particularly food preparation and related activities, are considered women's responsibilities and all the decisions related to them are taken by women. Therefore, these results could be understood as a reflection of the division of labor, gender relations and decision-making process in the Sudanese household. 相似文献