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کاربرد نوع شرط:
- جایگاه : پژوهشی
- مجله: Research Journal of Pharmacognosy
- نوع مقاله: Journal Article
- کلمات کلیدی: Safflower,oxidation reaction,alkaline solutions,carthamine,pigment yield
- چکیده:
- چکیده انگلیسی: Background and objectives: Safflower (Carthamus tinctorious L.) florets contain valuable red and yellow pigments and are used in food, textile dying, and pharmaceutical industries. Red carthamine pigment is formed from a yellow precursor, precarthamine, through an oxidation reaction at the end of flowers' maturation stage. The present study was conducted to find out the most effective procedure for extraction and purification of yellow and red pigments from safflower florets. Methods: Two different experiments were designed to assess the suitability of oxidant reagents (KMnO4 and H2O2) on the reddening of florets and different alkaline and organic solutions were used as the solvents (KNO3, Na2CO3, ethanol/hexane, methanol, and NaOH) in order to extract and purify the pigments. All obtained pigments were characterized chromatographically and spectrophotometrically for calculating the yield and evaluating purity of the extracted materials. Results: The results showed that KMnO4 and H2O2 treatments were significantly effective for increasing carthamine yield from safflower; but KMnO4 decreased the amount of yellow pigment extraction during the washing process of treated petals before extraction. Ethanol/hexane demonstrated to be effective in the extraction of yellow pigments, but it was not a good solvent for carthamine extraction. Except for the degassed bicarbonate which showed a high pigment yield, the other three solvents especially KNO3 did not appear to be of practical use for red pigment preparation. Conclusion: The present results showed that pretreatment of petals with hydrogen peroxide and then extracting by degassed solvents resulted in higher yield of red carthamine pigment, and also using reconditioned cellulose or cotton, instead of fresh cellulose, would reduce the cost.
- انتشار مقاله: 07-07-1393
- نویسندگان: E. Ghorbani,R. Hasani Keleshteri,M. Shahbazi,F. Moradi,M. Sadri
- مشاهده
- جایگاه : پژوهشی
- مجله: Journal of Nanostructures
- نوع مقاله: Journal Article
- کلمات کلیدی: Chitosan,Antibiotic,Silica,Electrospinning,Nanofiber
- چکیده:
- چکیده انگلیسی: The biocompatible and biodegradable polymer nanofiber with high potential for anti-bacterial coating are used for: multi-functional membranes, tissue engineering, wound dressings, drug delivery, artificial organs, vascular grafts and etc. Electrospinning nanofiber made of scaffolding due to characteristics such as high surface to volume ratio, high porosity and very fine pores are used for a wide range of applications. In this study, polymer composite nanofiber Silica/chitosan/poly (ethylene oxide) /cefepime antibiotic synthesis and antibacterial properties will be discussed. The optimum conditions for preparation of electrospun nanofiber were: voltage; 21 kV, feed rate; 0.5 mL/h, nozzle-collector distance; 10 cm, and chitosan/poly(ethylene oxide) weight ratio 90:10 and the volume ratio of chitosan/silica is 70:30. The antibacterial activity of composite scaffolds were tested by agar plate method by two type bacteria including Escherichia coli and Staphylococcus aureus. With the addition of the silica to chitosan, the hybrid was more biodegradable and improves the mechanical properties of biopolymer.
- انتشار مقاله: 19-12-1394
- نویسندگان: A. Bagheri Pebdeni,M. Sadri,H. Hosseini
- مشاهده
- جایگاه : پژوهشی
- مجله: Desert
- نوع مقاله: Journal Article
- کلمات کلیدی: Spatial Pattern,Trend Analysis,SPI indices,Drought Duration
- چکیده:
- چکیده انگلیسی: The present study was conducted to assess the changes in Iran's drought severity for the duration of 1964 to 2014. For this purpose, the spatial distribution of drought was annually and seasonally evaluated using climate data from 26 synoptic stations over Iranian territory based on standardized precipitation index (SPI). In this regard, the climate classification in the study area was performed applying Dermartone method. Moreover, the annual and seasonal values of SPI were calculated for the whole Iranian territory and each climate region. The SPI index for monotonic trend was calculated in each climate region utilizing Mann-Kendall and Theil Sen estimators. Our results implied that the minimum and maximum values of SPI (-3.86 and 2.89, respectively) appeared during spring in dry and Mediterranean climate regions. In addition, the maximum and minimum values of annual continuous SPI appeared in 1999-2004 and 1974-1982, respectively. The maximum and minimum values of seasonal continuous SPI also appeared for a duration of 9 years during summers respectively in the period of 1977 to 1985 and springs in the period of 2006 to 2014. The application of Mann-Kendall and Theil Sen estimator analyses revealed that 9 out of 26 stations had a significant decreasing SPI trend. Moreover, the annual and seasonal time series in moderately dry regions indicated a meaningfully decreasing trend in winter and annual SPI. Additionally, winter, spring, autumn and annual values of SPI had a meaningful decreasing trend in the Mediterranean climate region. In dry and very wet climate regions, no obvious trend was detected for the annual or seasonal SPI index.
- انتشار مقاله: 01-11-1399
- نویسندگان: A. Karbassi,M. Maghrebi,R. Noori,R. Lak,M. Sadrinasab
- مشاهده
- جایگاه : پژوهشی
- مجله: Desert
- نوع مقاله: Journal Article
- کلمات کلیدی: Persian Gulf,Sediment core,Paleo temperature,long-term metals concentration
- چکیده:
- چکیده انگلیسی: Long marine sedimentary cores can be effective in paleo-climate reconstruction. The present research aims at analyzing the temporal variation of temperature as an important climate parameter and also variations in metal concentrations (As, Ba, Cd, Li, Mo, Mg, Mn, Na, Pb, Sr, Zn, Fe, Ca, Al) of two long sedimentary cores at the Persian Gulf back to the Holocene. The obtained results revealed that the average elemental concentrations, apart from Ni, Sr, Ca and Na, are less than the shale value in both sedimentary cores. Moreover, the amount of varies from -1.31 versus 1.02 in Bushehr, to -1.69 versus 1.56 in Bandar Abbas sedimentary cores, respectively. In addition, change from -3.63 Vs -2.02 in Bushehr to -3.79 Vs -1.36 in Bandar Abbas sedimentary cores, respectively. Abrupt change in and can be seen in both sedimentary cores at two different periods (3000 to 5000 and 8000 to 9000 years ago). The maximum increase in temperature in sedimentary cores was at 0.4°C per 100 years in Bushehr and 0.01°C per 100 years in Bandar Abbas. The minimum temperature reached to -0.8°C per 100 years in Bushehr to -0.02°C per 100 years in Bandar Abbas sedimentary cores. Compared to the previously obtained temperatures in this research, there has been temperature changes in the last 40 years in the Persian Gulf, which indicates that the recent rate change in sea water temperature has been unprecedented.
- انتشار مقاله: 24-06-1397
- نویسندگان: A.R. Karbassi,M. Maghrebi,R. Lak,R. Noori,M. Sadrinasab
- مشاهده