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221.
Oat and oat products containing β-glucans are associated with many health claims. Both the level and molecular weight of β-glucans play an important role in determining the physiological efficacy of β-glucan in terms of health benefits, including reducing blood cholesterol levels. The objective of this study was to develop a probabilistic model to investigate the effect of various process stages in bread making on the level of β-glucan (BG) and its molecular weight (Mw) distribution using Monte Carlo simulation techniques. Various composite flours were formulated by substituting wheat flour (WF) with oat whole flour (OWF), oat refined flour (ORF), oat bran (OB) or rolled oats (RO). The baseline model predicted an overall mean reduction of 49% in BG in baked bread. The mean Mw of β-glucan in all composite flours was reduced following processing and baking from 1.22 to 0.77 × 106 (g/mol) for OWF + WF, 1.07 to 0.68 × 106 (g/mol) for ORF + WF, 1.17 to 0.75 × 106 (g/mol) for OB + WF and 1.25 to 0.80 × 106 (g/mol) for RO + WF. In all formulated breads, high molecular weight β-glucan was observed to be more susceptible to degradation compared with medium molecular weight and to lower molecular weight. A sensitivity analysis highlighted the negative influence of WF on β-glucan content and the BG reduction with fermentation time. The scenario analysis showed a positive influence on the level of BG with increase addition of oat flour in all formulated breads. The model was validated with experimental data and values were found to be within the confidence interval of predicted BG levels. This model facilitates the optimisation of various steps in the bread making process and highlights the potential for oat flour to improve the nutritional quality of baked bread.  相似文献   
222.
Fifty-five multiparous Holstein dairy cows were used to evaluate the singular and combined effects of somatotropin and monensin treatments during the late dry period on postpartum metabolism and production. Treatments were 1) control (C); 2) injection of exogenous bovine somatotropin (bST); 3) TMR top dressed with 300 mg of monensin/day (M); and 4) monensin and somatotropin in combination (bST+M) during the last 28 days before expected parturition. A 500-mg subcutaneous injection of sustained release somatotropin was administered adjacent to the tail head at d -28 and -14 relative to expected calving. Diet and management were the same for all cows after parturition. Production and intake were measured daily until 63 d in milk. Milk composition, blood metabolites, and body weight and condition score were measured weekly. Prepartum glucose, nonesterified fatty acid, and blood urea nitrogen concentrations were not different among treatments. Cows on the M treatment tended to have greater dry matter intake postpartum than those on the C treatment and 30% lower plasma nonesterified fatty acid concentrations during wk 1 postpartum than all other treatments. Milk yield and milk fat yield were not different among treatments, but milk fat percent tended to be lower for the bST+M treatment than the C treatment. Changes in plasma amino acid concentrations were consistent with mobilization of skeletal muscle protein, possibly for use in gluconeogenesis. Results from this study provide evidence that prepartum feeding of monensin reduced plasma nonesterified fatty acid concentrations and may improve glucose metabolism of the periparturient dairy cow.  相似文献   
223.
To investigate the cellular distribution of tumor‐promoting vs. non‐tumor‐promoting bryostatin analogues, we synthesized fluorescently labeled variants of two bryostatin derivatives that have previously shown either phorbol ester‐like or bryostatin‐like biological activity in U937 leukemia cells. These new fluorescent analogues both displayed high affinity for protein kinase C (PKC) binding and retained the basic properties of the parent unlabeled compounds in U937 assays. The fluorescent compounds showed similar patterns of intracellular distribution in cells, however; this argues against an existing hypothesis that various patterns of intracellular distribution are responsible for differences in biological activity. Upon further characterization, the fluorescent compounds revealed a slow rate of cellular uptake; correspondingly, they showed reduced activity for cellular responses that were only transient upon treatment with phorbol ester or bryostatin 1.  相似文献   
224.
Hafnium-based binary oxides have attracted considerable attention due to their robust ferroelectricity at the nanoscale and compatibility with silicon-based electronic technologies. To further promote the potential of Hafnium oxides for practical device applications, it is essential to effectively harness the interplay between structural symmetry, domain configuration, and ferroelectricity. Here, using Hf0.5Zr0.5O2/La0.67Sr0.33MnO3 (HZO/LSMO) heterostructures as a model system, the anisotropic strain-mediated symmetry engineering and ferroelectricity enhancement are systematically investigated. By growing the heterostructures on (110)-oriented perovskite substrates, considerable anisotropic strain is imposed on the LSMO bottom electrodes. Such an anisotropically-strained LSMO layer acts as a structural template and effectively tune the structural symmetry, polar/non-polar phase ratio, and ferroelectricity of the HZO top layer. Specifically, the anisotropic tensile strain stabilizes the ferroelectric rhombohedral and orthorhombic phases, thus enhancing the remnant polarization (Pr) up to 22 µC cm−2. In contrast, the anisotropic compressive strain facilitates the formation of non-ferroelectric tetragonal phases, leading to a suppressed Pr down to 8 µC cm−2. These findings provide a guideline for understanding and modulating the intrinsic structure-ferroelectricity relationship of HZO through anisotropic strain-mediated symmetry engineering, which may shed light on the development of hafnium-oxide-based electronic devices.  相似文献   
225.
In this work, a sintering route named cold sintering assisted two step sintering process (CSP-TS) is presented to prepare rutile TiO2 ceramics with submicron grain sizes. Cold sintering process at 300 °C with tetrabutyl titanate and water as the liquid phase yields a ‘green body’ with a relatively high density of ~80 %, and finally dense (98.5–99.8 %) rutile TiO2 ceramics with grain sizes of ~600 nm can be obtained in the second sintering process at 950?1000 °C. The microstructural analysis with SEM and TEM indicates that the CSP-TS samples sintered at 950 °C have an obvious phenomenon of recrystallization, accompanying by a decrease of amorphous phases and a formation of clear grain boundaries. Besides, the rutile TiO2 ceramics prepared by CSP-TS possess excellent microwave dielectric properties with relative permittivity of 92.0–98.4 and Q × f values of 27,800?31,900 GHz. Therefore, it is feasible to utilize CSP-TS to prepare ceramics with small grain sizes at low sintering temperatures.  相似文献   
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