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991.
Abdelmelek SB Greaves J Ishida KP Cooper WJ Song W 《Environmental science & technology》2011,45(8):3665-3671
The application of reverse osmosis (RO) in water intended for reuse is promising for assuring high water quality. However, one significant disadvantage is the need to dispose of the RO retentate (or reject water). Studies focusing on Pharmaceutical and Personal Care Products (PPCPs) have raised questions concerning their concentrations in the RO retentate. Advanced oxidation processes (AOPs) are alternatives for destroying these compounds in retentate that contains high concentration of effluent organic matter (EfOM) and other inorganic constituents. Twenty-seven PPCPs were screened in a RO retentate using solid phase extraction (SPE) and UPLC-MS/MS, and detailed degradation studies for 14 of the compounds were obtained. Based on the absolute hydroxyl radical (HO?) reaction rate constants for individual pharmaceutical compounds, and that of the RO retentate (EfOM and inorganic constituents), it was possible to model their destruction. Using excitation-emission matrix (EEM) fluorescence spectroscopy, the HO? oxidation of the EfOM could be observed through decreases in the retentate fluorescence. The decrease in the peak normally associated with proteins correlated well with the removal of the pharmaceutical compounds. These results suggest that fluorescence may be a suitable parameter for monitoring the degradation of PPCPs by AOPs in RO retentates. 相似文献
992.
Ancelet T Davy PK Mitchell T Trompetter WJ Markwitz A Weatherburn DC 《Environmental science & technology》2012,46(9):4767-4774
Particulate matter (PM) sources at two different sites in a rural town in New Zealand were investigated on an hourly time-scale. Streaker samplers were used to collect hourly, size-segregated PM(10-2.5) and PM(2.5) samples that were analyzed for elemental content using ion beam analysis techniques. Black carbon concentrations were determined using light reflection and PM(10) concentrations were recorded using colocated continuous PM monitors. PM(10) concentrations at both sites displayed a diurnal pattern, with hourly PM(10) concentration maxima in the evening (7 pm-midnight) and in the morning (7-9 am). One of the monitoring sites experienced consistently higher average PM(10) concentrations during every hour and analysis indicated that katabatic flows across the urban area contributed to the increased concentrations observed. Source apportionment using positive matrix factorization on the hourly data revealed four primary PM(10) sources for each site: biomass burning, motor vehicles, marine aerosol and crustal matter. Biomass burning was the most dominant source at both sites and was responsible for both the evening and morning PM(10) concentration peaks. The use of elemental speciation combined with PM(10) concentrations for source apportionment on an hourly time-scale has never been reported and provides unique and useful information on PM sources for air quality management. 相似文献
993.
994.
The effect of volatile compounds in white birch sticks obtained from four different geographical locations on the aroma of ice cream mix was investigated. Sensory evaluation, (specifically, a series of warmed-up paired comparisons) was conducted on stick-exposed ice cream mixes to determine whether aroma differences in those mixes could be detected. Batches of ice cream mix were exposed to the sticks and aged for 6 d at 4 degrees C and then assessed by the panelists by pairwise comparison. Findings suggest that differences in aroma of mixes that have been exposed to white birch sticks from four different geographical origins can be distinguished perceptually. 相似文献
995.
Protective effects of s-ethyl cysteine (SEC) and s-methyl cysteine (SMC) in kidney of diabetic mice were examined. SEC and SMC at 0.5, 1, 1.5, 2 g/L were added to the drinking water for 6 wk. Results showed that the intake of SEC or SMC alleviated body weight loss and urine output, as well as markedly decreased plasma blood urea nitrogen (BUN) and creatinine clearance (CCr) in diabetic mice (P < 0.05). The intake of SEC caused significantly dose-dependent increase in insulin and decrease in blood glucose, urinary albumin and type IV collagen (P < 0.05). SEC and SMC intake significantly and dose-dependently decreased malondialdehyde level and increased glutathione content in kidney (P < 0.05). The intake of these agents also increased renal GPx activity (P < 0.05), but there was no dose-dependent effect. SEC treatments dose-dependently decreased IL-6 and TNF-alpha levels, increased IL-4 and IL-10 levels, as well as upregulated IL-10 mRNA expression (P < 0.05). SMC treatments significantly suppressed renal IL-6 and TNF-alpha levels (P < 0.05), but did not affect IL-4 and IL-10 levels (P < 0.05). SEC or SMC intake significantly suppressed renal TGF-beta1 level and renal PKC activity (P < 0.05); however, only SEC treatments showed dose-dependent effect. SEC and SMC treatments significantly down-regulated mRNA expression of renal TGF-beta1 (P < 0.05), only SEC treatments had dose-dependent effects. Based on the observed antioxidative, antiinflammatory, and antifibrogenic effects, the supplement of SEC or SMC might be helpful for the prevention or treatment of diabetic kidney diseases. 相似文献
996.
Fulkerson WJ Davison TM Garcia SC Hough G Goddard ME Dobos R Blockey M 《Journal of dairy science》2008,91(2):826-839
A 5 yr whole-system study, beginning in June 1994, compared the productivity of high [HGM; Australian Breeding Value (ABV) of 49.1 kg of fat plus protein] and low [LGM; ABV of 2.3 kg of fat plus protein] genetic merit cows. Cows from both groups were fed at 3 levels of concentrate (C): 0.34 (low C), 0.84 (medium C), and 1.71 (high C) t of DM/cow per lactation. Thus, there were 6 treatments (farmlets) composed of 18 cows each. The 30 blocks of pasture on each farmlet were matched between farmlets for pasture growth before the study (and soil characteristics and aspect). Cows were culled, and pasture and feed use were managed so as not to bias any one treatment. Genetic merit, level of feeding, and their interaction were significant effects for protein content, protein/cow, and milk and protein/ha. For fat and milk yield/cow, genetic merit and level of feeding were significant, whereas there was no significant effect of genetic merit on fat content. The difference of 46.8 kg of fat plus protein yield between the ABV of HGM and LGM cows and the actual difference in production between the 2 groups was not significantly different except for low C (27 kg) cows. This was due to a 3-fold lower protein yield difference (6 kg/cow) compared with an ABV difference for protein yield of 17.9 kg/cow. The dramatic effect of treatment on protein is in line with differences in the mean protein content (2.89% for the HGM - low C cows compared with a mean of 3.02% for the remaining groups) and mean body condition score [4.3 for HGM - low C cows compared with 4.8 for the mean of the remaining groups (scale 1 to 8)], both indicators reflecting a higher negative energy balance in the HGM - low C cows. When individual cow production was plotted against ABV for production of milk or protein yield all relationships were quadratic, but the slope was relatively flat (low response to ABV) for the low C cows, steeper for the medium C cows and steepest (but not linear) for the high C cows. The relationship between ABV for fat yield and actual fat yield was linear for all levels of concentrate. The mean milk yield/ha from pasture for the 6 farmlets over the 5 yr was 11,868 L, 11,417 L, or 7,761 L for the HGM cows fed at low C, medium C, or high C, respectively, and 10,579 L, 9,800 L, or 5,812 L for LGM cows, fed at low C, medium C, or high C, respectively. The response to concentrates fed was very high for the HGM - medium C cows at 0.115 kg fat plus protein or 1.75 L milk/kg of concentrate fed, with comparable figures of 0.083 kg and 1.0 L, 0.86 kg and 1.47 L and 0.066 and 0.92 L/kg of concentrate fed for the HGM - high C, LGM - medium C, and LGM - high C, respectively. The results show a significant genetic merit by environment (level of feeding) interaction for reproduction and most production parameters when considered in terms of the individual cow and the whole farm system. 相似文献
997.
Davis KL Fulkerson WJ Garcia SC Dickeson D Barchia IM 《Journal of dairy science》2008,91(7):2604-2609
Economic viability of automatic milking systems (AMS) within an Australian pasture-based farming system will be largely determined by the throughput (cows milked/h), which is the result of processes occurring while the cow is in the AMS milking crate. Premilking udder preparation is automated and optional on all AMS. Yet, very few conventional farms in Australia conduct premilking teat preparation regimens, with the majority (78%) strategically washing only visibly dirty teats before milking cup attachment. The objective was to determine the impact of udder preparation in an AMS on the total time spent by cows in the AMS milking unit (crate time). An experiment was conducted with 80 lactating Holstein-Friesian cows in a crossover design over two 5-wk periods to determine the effect of premilking teat preparation (no wash vs. wash) on milk yield, milk harvest rates, and total crate time per milking session in an AMS. Within this study there was no significant effect of treatment on quarter milk conductivity (no wash = 4,858 vs. wash = 4,829 ± SE = 17 μS/cm), milk blood concentration (no wash = 115.7 vs. wash = 112.3 ± 7.3 ppm) or test-day somatic cell counts (no wash = 2.044 vs. wash = 2.039 ± 0.025 log10 SCC). There was similar total daily milk yield for the 2 treatments (no wash = 20.5 vs. wash = 20.1 ± 0.2 kg of milk), but a greater mean quarter milk flow rate resulting from the wash treatment (no wash = 0.950 vs. wash = 0.981 ± 0.013 kg of milk/min). The faster milking was not sufficient to counter the time associated with washing, resulting in longer crate time (no wash = 6.02 vs. wash = 7.12 ± 0.08 min/milking session) and therefore, lower harvest rate (no wash = 2.08 vs. wash = 1.74 ± 0.02 kg of milk/min crate time). Not washing teats would allow more efficient AMS utilization by potentially allowing more cows to be milked per machine, which would likely have a positive effect on the economic viability of this technology. The results indicate that a longer term study, investigating the effect of washing teats on udder health and milk quality, is warranted. 相似文献
998.
For the production of optically active ketoprofen, enzymatic resolution of racemic ketoprofen in an organic solvent has been accomplished via enantioselective esterification. Pharmacologically inactive (R)-ketoprofen is converted into the corresponding (R)-ester by this method. Enantioselectivity in lipase-catalyzed resolution of racemic ketoprofen was mainly dependent on the sources of lipase, alcohol moiety, organic solvent, and water content. Ethanol was used as the alkyl donor and the optimum water content required for highly efficient enzymatic resolution was determined to be 0.1-0.15% (v/v), which was maintained using salt hydrates such as Na2SO4 x 10H2O. (S)-Ketoprofen could be obtained with high enantioselectivity (E=15) in n-hexane supplemented with ethylene dichloride (20% (v/v)) using commercially available Candida antarctica lipase (Novozym 435). 相似文献
999.
Adaptive predictive multiplicative autoregressive model for medical image compression 总被引:1,自引:0,他引:1
In this paper, an adaptive predictive multiplicative autoregressive (APMAR) method is proposed for lossless medical image coding. The adaptive predictor is used for improving the prediction accuracy of encoded image blocks in our proposed method. Each block is first adaptively predicted by one of the seven predictors of the JPEG lossless mode and a local mean predictor. It is clear that the prediction accuracy of an adaptive predictor is better than that of a fixed predictor. Then the residual values are processed by the MAR model with Huffman coding. Comparisons with other methods [MAR, SMAR, adaptive JPEG (AJPEG)] on a series of test images show that our method is suitable for reversible medical image compression. 相似文献
1000.
Hacquebard M Vandenbranden M Malaisse WJ Ruysschaert JM Deckelbaum RJ Carpentier YA 《Lipids》2008,43(7):663-671
The present study determined alpha-tocopherol mass transfer from an alpha-tocopherol-rich emulsion to LDL and HDL, and assessed
the potential of different mechanisms to modulate alpha-tocopherol transfers. Emulsion particles rich in alpha-tocopherol
were incubated in vitro with physiological concentrations of LDL or HDL. The influence of plasma proteins was assessed by
adding human lipoprotein poor plasma (LPP) fraction with intact vs heat inactivated PLTP, or with a specific cholesteryl ester
transfer protein (CETP) inhibitor, or by adding purified PLTP or pig LPP which lacks CETP activity. After 4 h incubation in
absence of LPP, alpha-tocopherol content was increased by ~80% in LDL and ~160% in HDL. Addition of LPP markedly enhanced
alpha-tocopherol transfer leading to 350–400% enrichment in LDL or HDL at 4 h. Higher (~10 fold) enrichment was achieved after
20 h incubation with LPP. Facilitation of alpha-tocopherol transfer was (i) more than 50% higher with human vs pig LPP (despite
similar PLTP phospholipid transfer activity), (ii) reduced by specific CETP activity inhibition, (iii) not fully suppressed
by heat inactivation, and (iv) not restored by purified PLTP. In conclusion, alpha-tocopherol content in LDL and HDL can be
markedly raised by rapid transfer from an alpha-tocopherol-rich emulsion. Our results indicate that alpha-tocopherol mass
transfer between emulsion particles and lipoproteins is mediated by more than one single mechanism and that this transfer
may be facilitated not only by PLTP but likely also by other plasma proteins such as CETP. 相似文献