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21.
22.
A case of unicystic ameloblastoma which recurred after 15 years showing unusual histological features is reported. The prominent pseudo-glandular features present are described. This case highlights the importance of extensive histological examination for more characteristic features of ameloblastoma to reach a correct diagnosis. 相似文献
23.
Manaswita Nag 《Materials Research Bulletin》2007,42(9):1691-1704
In this paper, a simple and efficient methodology for the low-temperature synthesis of phase-pure nanocrystalline rutile TiO2 with tuned morphology is reported. Control on morphology has been achieved by simple variation of the hydrothermal process, starting with titanium-tetrachloride without using mineralizers, additives or templating agents. The X-ray diffraction (XRD) and selected area electron diffraction (SAED) patterns showed no other phases of TiO2 establishing the formation of phase-pure rutile titania in the entire temperature range of synthesis (40-150 °C) and most noticeably even at a considerably low temperature (40 °C). Fourier transform infrared (FT-IR) spectra strongly indicated the presence of hydroxyl group or surface adsorbed water and the thermogravimetry and differential thermo-gravimetry (TG-DTG) showed no phase change up to 1000 °C. A combination of reaction parameters (temperature, time) with a thorough transmission electron microscopy (TEM) study demonstrated the formation of phase-pure rutile titania nanocrystals as nano-rods, bunched nano-spindles or spherical nanoparticles depending on the hydrothermal reaction conditions. The photocatalytic activity of the synthesized nanocrystals has been successfully evaluated on the photodegradation of methyl orange (MO), a well-known pollutant azo-dye, as a model reaction. 相似文献
24.
Toughness of rigid thermoplastic is an important mechanical property in polymer technology. In the present study, toughening of waste polypropylene (WPP) with ethylene–propylene–diene monomer (EPDM) rubber at different loading levels was carried out by melt blending at 180 °C. The EPDM-toughened WPP samples were characterized for its thermo-mechanical properties. The effect of carbon black (5 wt%) as a functional filler in WPP/EPDM to impart UV protection was also studied. The test sheets were subjected to natural weathering in variable climatic conditions for a 4-month period of time and were taken out at regular intervals for characterization. The waste PP underwent excessive degradation as the mechanical strength properties such as tensile, flexural and impact strengths were reduced drastically. On the other hand, WPP containing varying proportions of EPDM and carbon black showed better retention of strength properties. The percentage degree of crystallinity has been unusually increased after the environmental degradation due to chemi-crystallization. The impact-modified WPP which contains carbon black retained the processability even after the environmental aging. After aging, the non-stabilized systems were shown extensive change, whereas the structural integrity has been well retained of the toughened WPP containing carbon black as was evident from SEM and optical photomicroscopy. 相似文献
25.
Miniband parameters for a semiconductor superlattice are worked out using a Kronig Penney type of model potential distribution in the individual layers, and the results are compared with those obtained by using a constant electron effective mass. It is concluded that the nonparabolicity in the energy bands alter the miniband parameters significantly and the exact E−k relation for the electrons is required to be known for obtaining quantitatively correct results. 相似文献
26.
The structure of amorphous semiconductors has become the subject of intense study in recent years. In this paper, the models,
that have been constructed and applied to represent the structures, have been briefly reviewed. Details of the construction
of continuous random network (CRN) models have been presented and a comparative study of the microcrystallite model and the
random network model has been made in the light of their recent applications. 相似文献
27.
28.
Antonella De Leonardis Vincenzo Macciola Giuseppe Lustrato Giancarlo Ranalli Ahindra Nag 《European Food Research and Technology》2010,230(3):405-410
In the last few decades, biotechnological applications of phenoloxidase enzymes have become an area of significant interest.
In this study, sunflower seeds, seedlings and defatted mill cake were investigated as possible plant source of polyphenoloxidase
(PPO). Noticeable variation of chlorogenic acid concentration in each raw material has undoubtedly proven that only sunflower
seedlings have significant amounts of active PPO. The activity of the enzymes was assessed by measuring the molar decrease
of caffeic acid. Isolated protein powders from each raw material confirmed the presence of PPO only in the seedlings. Catalytic
action of the PPO of seedlings was compared to that of the commercial laccase from Trametes versicolor. Sunflower PPO was selectively active on caffeic and chlorogenic acids, less active on ferulic acid and not active on mono-phenols
and gallic acid. Conversely, laccase was highly active on all the assessed phenols. PPO activity was good in a large range
of pH (4–8), whilst it was approximately halved in solutions containing 35% ethyl alcohol (v/v), 500 mg L−1 citric acid and finally 200 mg L−1 sulphur dioxide. In conclusion, sunflower seedlings can be considered a potential and interesting plant source of PPO. Sunflower
PPO could be used to oxidise selectively o-diphenols, for example in alcoholic and nonalcoholic beverages. 相似文献
29.
Physicochemical Characterization of Chrysin‐Derivative‐Loaded Nanostructured Lipid Carriers with Special Reference to Anticancer Activity 下载免费PDF全文
Gourab Karmakar Prasant Nahak Priyam Chettri Biplab Roy Pritam Guha Koji Tsuchiya Kanjiro Torigoe Anoop Kumar Ranendu K. Nath Sukhen Bhowmik Utpal C. De Kaushik Nag Amiya K. Panda 《Journal of surfactants and detergents》2018,21(3):421-432
Homologues long‐chain chrysin derivatives (LCD, C n: 8–18) were synthesized and incorporated into nanostructured lipid carriers (NLC) with the aim to treat human neuroblastoma. Mutual miscibility and attractive interactions among the NLC components, namely tripalmitin (TP), cetyl palmitate (CP), oleic acid (OA), and the chrysin (CHR) derivatives (LCD) at the air–water interface were assessed by the Langmuir monolayer approach. Optimum combination for the NLC formulations was found to be 2:2:1 (M/M/M) for TP/CP/OA, respectively. NLC formulations, both in the absence and presence of LCD, were characterized by combined dynamic light scattering, electron microscopy, atomic force microscopy, and differential scanning calorimetry. The size and zeta potential of the NLC formulations were found in the range 200–350 nm and ?12 to ?18 mV, respectively. Encapsulation efficiency and release kinetics of CHR and LCD when loaded into NLC were also evaluated. LCD exhibited maximum incorporation, drug‐loading capacity, and sustained release because of its enhanced hydrophobicity. Superior incorporation efficiency and sustained‐release profile of LCD were able to enhance their anticancer activity against human neuroblastoma cell lines, compared to CHR, making them promising agents in combating cancer. 相似文献
30.
Manju Bala T. N. Nag Sandeep Kumar Manmohan Vyas Arun Kumar N. S. Bhogal 《Journal of the American Oil Chemists' Society》2011,88(4):559-562
The chemical characteristics of Pongamia pinnata seeds, focussing on proximate composition and the fatty acid profile of its oil, are presented. The proximate composition
of P. pinnata seeds was: 3.8% ash, 9.7% sugar, 7.07% protein, 24% oil, 10.7% free amino acids, and 0.24% free fatty acids. The oil was
extracted from seeds by use of different solvents and the highest yield (29%) was obtained by use of n-hexane. Monounsaturated and polyunsaturated fatty acids accounted for 63.3 and 22.9%, respectively, of the seed oil. Oleic
acid was the major fatty acid but a substantial amount of erucic acid was also detected; this was not reported in previous
studies. The level of erucic acid and the presence of toxic flavonoids, for example karanjin, pongapin, and pongaglabrin,
render the oil inedible according to WHO recommendations. However, low levels of saturated and polyunsaturated fatty acids
with desirable cetane number and iodine value suggest potential for application as a biodiesel fuel. 相似文献