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排序方式: 共有882条查询结果,搜索用时 15 毫秒
871.
CM Cuttica P Sessarego P Ponzani MR Falivene S Valenti D De Martini M Giusti 《Canadian Metallurgical Quarterly》1997,88(6):264-268
Specific inhibition of mammalian genes is possible through the use of antisense oligonucleotides (AS ODNs) or ribozymes. These strategies have led to a better understanding of several cellular and molecular mechanisms, among which cancer development. Recently, these strategies have been applied also for therapeutical purposes in diseases such as AIDS and cancer. In some of these therapeutical trials the antisense strategy is combined with gene transfer technology: the AS ODN or the ribozyme are expressed within the cell by the use of adenoviral or retroviral vectors. However, many difficulties have still to be overcome before ODNs and ribozymes can be used routinely in the clinic. 相似文献
872.
IB Mandell JG Buchanan-Smith BJ Holub CP Campbell 《Canadian Metallurgical Quarterly》1997,75(4):910-919
We investigated the effects of fish meal (FM) in beef cattle diets on growth performance, carcass characteristics, and fatty acid (FA) composition of longissimus muscle in 63 yearling steers (335 +/- 23 kg). High-moisture corn and alfalfa silage diets were supplemented with either a corn gluten/blood meal mixture or FM at 10% of the diet. Fish meal contained (as-is basis) 5.87 g/kg eicosapentaenoic acid (EPA) and 9.84 g/kg docosahexaenoic acid (DHA). Seven strategies were developed to feed either a control diet (no FM) or diets containing 5 or 10% FM with FM fed for either 56, 112, or 168 d before slaughter. Average daily gain and feed efficiency were not affected (P > .10) by FM feeding but DMI decreased. Within FM diets, cattle fed 5% FM consumed more (P < .01) DM and gained more (P < .02) than cattle fed 10% FM. Carcass traits were not affected (P > .05) by feeding strategy except for fatter (P < .05) and lower (P < .06) yielding carcasses in cattle fed 5 vs 10% FM diets. Fish meal feeding increased (P < .01) concentrations of (n-3) FA, including EPA and DHA, and decreased (P < .05) concentrations of arachidonic acid. Increasing the amount of dietary FM further increased (P < .01) concentrations of EPA and DHA and decreased (P < .05) concentrations of (n-6) FA. We estimate that a 114-g steak from cattle fed 10% FM would supply 35 to 90% of the current average daily intake of EPA and DHA in North America. The results indicate that FM may have a role in niche marketing of beef provided that eating quality is not compromised. 相似文献
873.
874.
We are introducing a new high-capacity thermoluminescent dosemeter (TLD) system to measure the whole body values of H(p)(10) and H(p)(0.07) from photons for use in individual monitoring services. Small and light-weight badges allow a convenient application in a wide variety of workplaces with photon radiation from 20 keV to at least 7 MeV. The main advantage of this system will be the large capacity of ~ 100,000 dosemeters per month at costs equivalent to the current film monitoring. The hot-pressed thin-layer TL detector (LiF:Mg,Ti) is welded onto an aluminium substrate and provided with a data matrix code for automatic processing. The detector holder has been optimised, that no additional filter is necessary. The new designed TLD reader with readout times <10 s will allow a large throughput and a considerable degree of automation. 相似文献
875.
Stefano Mariani Roberto Martini Alberto Corigliano Marco Beghi 《Computational Materials Science》2011,50(10):2993-3004
We present a numerical study aimed to define the overall elastic domain of thin polysilicon films subjected to in-plane loadings. Homogenized properties are obtained for digital polycrystalline microstructures, generated in a representative volume element (RVE) through Voronoi tessellations. To locate the elastic limit, three micromechanical sources of dissipation are allowed for: (i) trans-granular cracking, as due to tensile stresses attaining the local strength inside silicon grains; (ii) inter-granular failure, as due to coupled normal-shear tractions attaining a local effective strength along grain boundaries; (iii) trans-granular phase transformation, as due to compressive stresses attaining a critical threshold inside silicon grains.Results of the homogenization procedure show that Rankine-type overall domains are too crude approximations to the polysilicon elastic envelope, since corners arise because of switching among the three dissipative modes allowed for. Outcomes of the analysis allow also to estimate the size of the RVE required to get objective overall polysilicon properties: according to data already available in the literature, it is shown that the RVE has to gather at least a few hundreds of grains. 相似文献
876.
Melissa Abigail Marsh Silvana Martini 《Journal of the American Oil Chemists' Society》2022,99(4):313-330
The objective of this study was to identify the physical properties of an interesterified soybean oil (EIESOY), containing 45% saturated fatty acids (SFA), that correlates with high oil binding capacity (OBC) and low oil loss (OL). In this study, three EIESOY samples were analyzed; a 100% sample, a 50% sample diluted with 50% soybean oil, and a 20% sample diluted with 80% soybean oil. All samples were crystallized using fast (7.78°C/min) and slow (0.1°C/min) cooling rates as well as with and without high-intensity ultrasound (HIU, 20 kHz). The 100%, 50%, and 20% samples were crystallized at 38.5, 27.0, and 22.0°C, respectively. HIU was applied at the onset of crystallization and all samples were allowed to crystallize isothermally for 90 min. After 90 min, physical properties such as crystal microstructure, hardness, solid fat content (SFC), elasticity, and melting behavior were evaluated. Physical properties were also measured after storage for 48 h at 22 and 5°C. Results show that OBC was positively correlated with hardness, G′, and SFC after 48 h (r = 0.738, p = 0.006; r = 0.639, p = 0.025; r = 0.695, p = 0.012; respectively), OL was negatively correlated with hardness after 48 h (r = −0.696, p < 0.001), G′ after 90 min and 48 h (r = −0.704, p < 0.001; r = −0.590, p = 0.002), and SFC after 90 min and 48 h (r = −0.722, p < 0.001; r = −0.788, p < 0.001). Neither OBC nor OL were correlated with crystal diameter or the number of crystals. 相似文献
877.
N. Garg S. Martini D.W. Britt M.K. Walsh 《Food research international (Ottawa, Ont.)》2010,43(4):1111-1115
Lactose-amines were synthesized with hexadecyl-amide and lactose via the Maillard reaction and their emulsion stabilization properties were investigated. Lactose-amines were synthesized using two different constant heating (4 and 8 h) and two different heating/cooling cycles (12 and 24 h). Each lactose-amine sample was used as an emulsifier in 20:80 ratio oil-in-water emulsions at four different concentrations (0.01%, 0.05%, 0.1%, and 1%). Emulsion stability was monitored by measuring the oil droplet sizes and the extent of destabilization via clarification over 5 days. At 1% concentrations, emulsions prepared with lactose-amines synthesized for 4, 12, and 24 h were as stable as the whey protein positive control emulsion. The 8 h lactose-amine sample resulted in a less stable emulsion. We assume the difference is related to the amount of heat this sample was exposed to during synthesis, with extensive heat leading to advanced Maillard products, which possessed reduced emulsification properties. 相似文献
878.
This research employed power ultrasound (US) to decrease the turbidity of whey suspensions. US was applied using a 20 kHz generator and different power levels (3 and 15 W) for different application times (5 and 15 min) at different temperatures (20, 60 °C, and no temperature control [NTC]) to whey suspensions obtained at 4 different steps in a commercial process. The whey suspensions varied from 6.9 to 30.2% solids and 13.5 to 88% protein. This research shows an approximately 90% decrease in turbidity when US was applied to a whey suspension of 28.2% of solids containing 35.6% of protein on a dry basis. The greatest decrease in turbidity was observed when US was applied for 15 min using 15 W of electrical power at 60 °C and NTC conditions. Surprisingly, when US was used in whey suspensions containing 88.0% protein an increase in turbidity of samples was observed. 相似文献
879.
Aging of cream is an important process to manage production time and to produce butter with consistent quality. The objective of this study was to evaluate the combined effect of temperature (5, 10, and 15°C) and agitation rate (0, 40, and 240 rpm) during aging of cream on the physical properties of cream and butter in a model system. Cream's solid fat content (SFC), melting behavior, and droplet size distribution were measured during and after 90 min of aging. Butter physical properties such as melting behavior, water content, and hardness were measured. The effects of agitation on SFC and droplet size are dependent on aging and churning temperature. Solid fat content increased faster at 5°C, and the maximum SFC was the highest at this temperature. An effect of agitation on SFC was observed only when cream was aged at 15°C. Agitating cream at 40 rpm increased the droplet size regardless of aging temperature. Two melting peaks, medium melting fraction (MMF) and high melting fraction (HMF), were found in cream samples aged at 5 and 10°C, but only a HMF melting peak was seen in the cream aged at 15°C. The enthalpy of MMF in the cream aged at 10°C with 40 rpm and without agitation was significantly lower than that in samples aged at 5°C regardless of agitation rate. Butter can be formed only from cream aged under certain conditions during 14.5 min of churning, which are 5°C with high agitation and 10°C regardless of agitation level. Butter produced with cream aged at 5°C with high agitation showed significantly higher MMF and total enthalpy values. However, no significant difference in enthalpy values was observed among the butter samples made from the cream aged at 10°C. Further crystallization of MMF occurred in the butter produced with cream aged at 10°C during 24 h of storage at 5°C, whereas no further crystallization occurred in the butter made with the cream aged at 5°C with high agitation. The hardest butter was obtained when cream was aged at 5°C with 240 rpm and at 10°C with 40 rpm. Softer butter was obtained when cream aged at 10°C with 240 rpm was used. This butter also had the highest water content. This study shows that butter hardness can be tailored by changing the aging conditions of the cream. Cream can be aged at higher temperature with low agitation without altering the hardness of butter. These results will help dairy producers to optimize butter making processes to obtain desired properties in the final product. 相似文献
880.
Short communication: Technological and seasonal variations of vitamin D and other nutritional components in donkey milk 总被引:1,自引:0,他引:1
Mina Martini Iolanda Altomonte Rosario Licitra Federica Salari 《Journal of dairy science》2018,101(10):8721-8725
Vitamin D is an essential nutrient that plays a crucial role in calcium homeostasis and bone metabolism and also acts as a hormone. Although several studies on the content of vitamin D in bovine milk have been conducted, little information is available regarding donkey milk. In the context of the nutritional assessment of donkey milk, the aim of this study was to assess the vitamin D content in donkey milk and its chemical profile, with particular reference to seasonal and technological modifications after pasteurization. The study was conducted on a dairy farm that produces donkey milk for human consumption located in central Italy. At sampling time, an aliquot of total bulk milk production was sampled before and after pasteurization (63°C for 30 min without homogenization) with a total of 20 raw and 20 pasteurized milk samples. The samples were collected for 10 mo, every 15 d, from May to February 2017. All the samples were analyzed for the chemical composition and vitamin D2 and D3 content by HPLC after saponification. The donkey milk analyzed showed a higher average vitamin D content (raw milk: vitamin D2 = 1.68, vitamin D3 = 0.60 μg/100 mL; pasteurized milk: vitamin D2 = 1.38, vitamin D3 = 0.30 μg/100 mL) than reported for bovine and human milk. The results of the effect of pasteurization on milk did not highlight significant differences in the total content of vitamin D. However, vitamin D3 has a poor thermal stability, which led to a significant reduction in content in pasteurized milk compared with raw milk. The total vitamin D content of donkey milk did not show significant variations between seasons; however, a higher concentration of vitamin D3 was found in spring and summer. In conclusion, raw and pasteurized donkey milk showed a high content of vitamin D, which could be useful in meeting the deficiencies of this vitamin in humans. Further investigations are needed to improve the vitamin D content in donkey milk by increasing its endogenous synthesis or its transfer in milk and to clarify other variability factors. 相似文献