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261.
262.
Journal of Materials Science - Ceria-zirconia solid solution (Ce0.5Zr0.5O2)-supported Ni catalyst (15 wt. %) is prepared by one-step co-precipitation followed by calcination reduction for...  相似文献   
263.
In this study, we report the effects of caffeine on angiogenesis in zebrafish embryos both during normal development and after exposure to Fibroblast Growth Factor 2 (FGF2). As markers of angiogenesis, we measured the length and width of intersegmental vessels (ISVs), performed whole-mount in situ hybridization with fli1 and cadh5 vascular markers, and counted the number of interconnecting vessels (ICVs) in sub-intestinal venous plexus (SIVP). In addition, we measured angiogenesis after performing zebrafish yolk membrane (ZFYM) assay with microinjection of fibroblast growth factor 2 (FGF2) and perivitelline tumor xenograft assay with microinjection of tumorigenic FGF2-overexpressing endothelial (FGF2-T-MAE) cells. The results showed that caffeine treatment causes a shortening and thinning of ISVs along with a decreased expression of the vascular marker genes and a decrease in the number of ICVs in the SIVP. Caffeine was also able to block angiogenesis induced by exogenous FGF2 or FGF2-producing cells. Overall, our results are suggestive of the inhibitory effect of caffeine in both direct and indirect angiogenesis.  相似文献   
264.
Journal of Mechanical Science and Technology - Six-legged hexapod walking robots are well-known for their intrinsic stability during navigation and 6-DoF object manipulation. The robot must be...  相似文献   
265.
Guerrini L  Hartsuiker L  Manohar S  Otto C 《Nanoscale》2011,3(10):4247-4253
NIR-dye encoded gold nanoparticles (GNP) are rapidly emerging as contrast agents in many bio-imaging/sensing applications. The coding process is usually carried out without control or a clear understanding of the metal-liquid interface properties which, in contrast, are critical in determining the type and extension of dye-metal interaction. In this paper, we investigated the effect of gold surface composition on the adsorption of indocyanine green (ICG) on GNP, simulating the surface conditions of gold nanorods on citrate-capped gold nanospheres. These substrates allowed a careful control of the metal-liquid interface composition and, thus, detailed absorption and fluorescence concentration studies of the effects of each individual chemical in the colloidal solution (i.e. bromide anions, cetyl trimethylammonium ions and Ag(+) ions) on the ICG-gold interaction. This study reveals the drastic effect that these experimental parameters can have on the ICG adsorption on GNP.  相似文献   
266.
Amyloglucosidase from Rhizopus mold and β-glucosidase from sweet almond, catalysed synthesis of vanillyl-maltoside was optimized using response surface methodology. A central composite rotatable design involving 32 experiments of five variables at five levels was employed. Among the variables employed, glucosidases (10–50% w/w of maltose), vanillin (0.5–2.5 mmol), incubation period (24–120 h), buffer volume 0.4–2.0 ml (0.04–0.2 mM) and pH (4.0–8.0); enzyme, buffer concentration and buffer pH were found to be significant with both the enzymes. Surface plots generated clearly brought out the maltosylation behaviour of the two glucosidases in this reaction with both the enzymes exhibiting yields in the range 5–60%. Saddle-shaped surface plots observed with both the enzymes exhibited total reversal of the maltosylation behaviour at certain critical crossover points like 30% (w/w maltose) enzyme concentration, buffer pH 6.0 and a buffer concentration of 1.25 ml (0.125 mM), implying that a critical enzyme to buffer concentration and pH dictate the extent of vanillin maltosylation. Validation experiments conducted at certain random selected conditions as well as those conducted at optimum conditions obtained from the reduced model showed good correspondence between predicted and experimental yields.  相似文献   
267.
Models capable of predicting the product quality of Gulab jamun using sugar and a sugar substitute have been developed using response surface methodology (RSM) and applied to determine the optimum processing conditions. Box–Behnken design was used considering three independent variables, namely concentration (°B) of syrup, its temperature and time of soaking, each at three different levels. The dependent variable or response measured for each treatment was a sensory score for overall quality, which is taken as a combination of the sensory impact of colour, appearance, texture, mouthfeel, taste and aroma. According to RSM, the optimum score for overall quality attained for Gulab jamun prepared with sugar was 7.7, obtained at processing conditions of 51°B syrup, 54 °C and 4 h soaking, whereas for the Gulab jamun prepared with the sugar substitute, sorbitol, a maximum overall quality score of 8.0 was obtained at processing conditions of 54°B syrup, 65 °C and 3 h soaking. These processing conditions were found to correlate with those of experimental conditions.  相似文献   
268.
The hydrodynamic characteristics of a pulsed sieve plate extraction column (PSPEC) was studied experimentally using two different liquid phase systems, namely water/kerosene and 30%TBP (tributyl phosphate) in NPH (normal paraffin hydrocarbon)/0.3 M HNO3. The aqueous phase as the dispersed phase and the organic phase as the continuous phase (phase reversal) and vice versa (normal phase operation) studies in a pulsed sieve plate extraction column 0.076 m in diameter and 1 m height are presented in this paper. The hydrodynamic properties like drop size and holdup are characterized as a function of various operating parameters namely pulse velocity, dispersed phase and continuous phase velocity and duty cycle of pulsing. Flooding in the column was also investigated for the changes involving flow ratio of continuous phase to that of the dispersed phase for both insufficient and excessive pulsing. It has been observed that phase reversal mode of operation is not efficient as compared to normal phase operation for the PSPEC.  相似文献   
269.
The internal resistance Rint of a mediator-less microbial fuel cell (MFC) has been determined as a function of cell voltage using electrochemical impedance spectroscopy (EIS) for a MFC with and without Shewanella oneidensis MR-1. The same tests were performed for a MFC containing small stainless steel (SS) balls in the anode compartment with a graphite feeder electrode as in a packed bed cell. It has been found that Rint decreased with decreasing cell voltage as the increasing current flow decreases the polarization resistance of the anode and the cathode. The ohmic components of Rint played a very minor role. In the presence of MR-1 Rint was lower by a factor of about 100 than Rint of the MFC with buffer and lactate as anolyte. Rint was also significantly lower for the anode containing SS balls with buffer and lactate as anolyte. For the MFC containing SS balls in the anode compartment no significant further decrease of Rint could be obtained when MR-1 was added to the anolyte since in this case the polarization resistance of the anode was lower than that of the cathode. Similar trends were observed in the cell voltage (V)-current (I) curves that were obtained using potentiodynamic sweeps and the power (P)-V curves that were calculated from the V-I curves.  相似文献   
270.
The essential oils from dried leaves of Lavandula bipinnata (Roth) Kuntze (Lamiaceae), obtained by soxhlet extraction was analysed by gas chromatography–mass spectrometry (GC–MS) and was evaluated for in vitro antimicrobial activity. The most common components usually found in lavender essential oils were present in the oil samples analysed, out of 43 peaks, 29 components, which constitute 72.38%, were identified in the essential oil. The major constituents were transcarveol (18.93%), pulegone (8.45%), camphor (7.09%) and menthol (5.89%). Other constituents present in fairly good amounts are pipertone (4.65%), caryophyllene oxide (3.68%), linalyl acetate (3.37%) and bicyclogermacrene (3.09%). The essential oil was screened for antimicrobial activity by disc diffusion assay and minimum inhibitory concentration (MIC) against bacteria and fungus. Results reveal that L. bipinnata essential oils are inhibitory against the tested bacteria and fungal strains.  相似文献   
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