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31.
An intermediate molecular weight contrast agent P760 was used to investigate the ability of multi-slice dynamic contrast-enhanced MRI (DCE-MRI) to distinguish metastatic from non-metastatic rodent prostate tumors. Non-metastatic AT2.1 and metastatic AT3.1 prostate tumors originally derived from the Dunning prostate cancer model were implanted on the hind leg of Copenhagen rats. Multi-sliced DCE-MRI data were acquired on a SIGNA 1.5 T scanner and analyzed using a recently developed empirical mathematical model. The P760 multi-slice DCE-MRI data in combination with the empirical mathematical model successfully distinguished between metastatic and non-metastatic rodent prostate tumors. Specifically, fitting the data with the empirical model showed that metastatic tumors had significantly faster contrast media uptake (p<0.001) and slower washout rates (p<0.01) than non-metastatic tumors  相似文献   
32.
Amino acid (AA) sequences of 807 bioactive peptides from foods of animal origin were examined in order to correlate peptide structure with activity (antihypertensive, antioxidative, immunomodulatory, antimicrobial, hypolipidemic, antithrombotic, and opioid) and stability in vivo. Food sources, such as milk, meat, eggs, and marine products, show different frequencies of bioactive peptides exhibiting specific effects. There is a correlation of peptide structure and effect, depending on type and position of AA. Opioid peptides contain a high percentage of aromatic AA residues, while antimicrobial peptides show an excess of positively charged AAs. AA residue position is significant, with those in the first and penultimate positions having the biggest effects on peptide activity. Peptides that have activity in vivo contain a high percentage (67%) of proline residues, but the positions of proline in the sequence depend on the length of the peptide. We also discuss the influence of processing on activity of these peptides, as well as methods for predicting release from the source protein and activity of peptides.  相似文献   
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34.
The Bukuljac cheese is traditionally homemade cheese, produced from heat-treated goat's milk without the addition of any bacterial starter culture. The presence of lactic acid bacteria (LAB) in Bukuljac cheese has been analyzed by using a polyphasic approach including microbiological and molecular methods such as rep-PCR with (GTG)5 primer. Lactobacillus paracasei subsp. paracasei represents a dominant strain in the microflora of analyzed cheese. Out of 55 Gram-positive and catalase-negative isolates, 48 belonged to L. paracasei subsp. paracasei species. Besides lactobacilli, five Lactococcus lactis subsp. lactis and two Enterococcus faecalis were found. Results of PCR-denaturing gradient gel electrophoresis (DGGE) of DNA extracted directly from the fresh cheese revealed the presence of Leuconostoc mesenteroides. Only lactobacilli showed a high proteolytic activity and hydrolyzed alpha(s1)- and beta-caseins. They are also producers of diacetyl. In addition, 34 out of 55 isolates, all determined as lactobacilli, showed the ability of auto-aggregation. Among 55 isolates, 50 also exhibited antimicrobial activity.  相似文献   
35.
This study focused on how the formation of phosphosilicate glass (PSG) film affects the solar cell emitter profile when using an inline ultrasonic mist phosphoric acid source and an inline diffusion furnace. This investigation used a novel approach, whereby the samples were extracted from the inline furnace mid‐process that allowed for the investigation of incompletely formed PSGs. All experimentation was conducted at BP Solar Australia. Total Gravimetric Analysis found that the dilute phosphoric acid dehydrates to form a high concentration phosphoric acid layer on the top surface. X‐ray photoelectron spectroscopy then showed this top surface reacts with the silicon and is reduced to form silicon phosphide. ECV results then demonstrated that the sheet resistance and emitter surface concentration of phosphorus is dependent upon the ratio of phosphide to total phosphorus in the PSG film. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   
36.
In order to produce fermented sausages with prebiotic fibre and improved fatty acid composition, 16% of pork back fat was replaced with inulin gelled suspension (I) and inulin linseed oil gelled emulsion (IO). Physico-chemical analysis, fatty acid profiles, lipid oxidation, microbiological, textural, colour and sensory analysis were carried out. The fat content was lower in I (31.38%) and IO (35.36%) modified sausages compared to control (44.37%) (< 0.05). IO sausages had lower SFA and MUFA and higher PUFA content with an improved n-6/n-3 ratio (2.23) (< 0.05) and α-linolenic acid increment (5.74 g per 100 g). Reformulation led to decrease in springiness, chewiness and hardness and increase in adhesiveness of the sausages. Modified sausages had lower L* and higher a* values, while b* values of I sausages did not differ compared to control sausages. Modified sausages were acceptable regarding all sensory attributes. Lipid oxidation parameters showed higher susceptibility to oxidation and lipolysis in IO sausages.  相似文献   
37.
Whey represents a significant dairy industry by-product that has recently received due attention based on the rich nutrient composition and significant transformation potential. Hereby, we investigated a possibility of whey lactose bioconversion into prebiotic compounds, galacto-oligosaccharides (GOS) using β-galactosidase transgalactosylation activity. The results showed that whey could be successfully used for GOS synthesis, since the highest GOS concentration (around 62 g L−1) was obtained batchwise using 40% (w/w) sweet whey powder solution under optimum conditions (50°C, pH 4.5). Nevertheless, an efficient immobilized preparation using methacrylic Lifetech ECR8409 immobilization carrier was developed, enabling additional process improvement and ensuring at least 4 reaction cycles with unchanged yields and 2.5- fold enhanced productivity in comparison to the soluble enzyme. Therefore, this study provides a valuable contribution to the efficient and economical valorization of whey, which can be further on utilized as functional food and feed constituent.  相似文献   
38.
Synthesis and subsequent deposition of sub-micron spherical RuO2/TiO2 particles onto titanium were performed by continuous process in two connected reactors, exclusively applied for this purpose. Synthesis of particles was achieved by ultrasonic spray pyrolysis method in the first reactor. The deposition of thus produced RuO2/TiO2 onto an expanded titanium substrate was performed at 500 °C afterwards in the second, specially constructed, reactor equipped by high-voltage electrostatic field. Basic electrochemical properties of the obtained RuO2/TiO2 particles were checked in a form of the coating on Ti deposited from the suspension of the material produced in the first reactor. Thus prepared anode was investigated by cyclic voltammetry (CV), polarization measurements in O2 (OER) and Cl2 (CER) evolution and the accelerated stability test in diluted chloride solution. The morphology and composition of the deposited RuO2/TiO2 were checked by scanning electron microscopy/energy dispersive X-ray spectroscopy analysis. Analysis of the results obtained for OER and CER showed that Tafel slopes for these reactions were in accordance with the values for this kind of material. The CV response was of usual characteristics too. The accelerated stability test revealed acceptable anode stability.  相似文献   
39.
This paper presents an enrollment management model by applying artificial neural network (ANN). The aim of the research, which has been presented in this paper, is to show that ANNs are more successful in predicting than the classical statistical method – regression analysis (logistic regression). Both predictive models, no matter whether they are based on ANNs or logistic regression, offer satisfactory predictive results, and they can offer support in the decision-making process. However, the model based on neural networks shows certain advantages. ANNs demand understanding of functional connection between independent and dependent variables in order to evaluate the model. Also, they adapt easily to related independent variables, without the appearance of the problem of multicollinearity. In contrast to logistic regression, neural networks can recognize the appearance of nonlinearity and interactions in input data, and they can react on time.  相似文献   
40.
The use of wireless sensor network (WSN) is essential for gathering data and implementation of information and control technologies in precision agriculture. The efficiency of such smart system strongly depends on WSN reliability and durability, which is highly influenced by wireless channel. Relaying of the collected data over the intermediate nodes has been proven as a good strategy for WSNs. In this paper we assume amplify-and-forward relaying strategy with variable gain amplification. In order to improve system performance we propose implementation of polarization diversity. It is assumed that all communication links are influenced by Rician fading. Thus, in the case of polarization diversity, link between the source and the relay is characterized as two correlated and non-identical Rician fading channels. In this paper, we present a novel analytical model for determining the outage probability of such system, which is applicable to various fading scenarios described with different Rician K factors and average signal to noise ratios (SNR), as well as different level of diversity signals correlation and cross-polar discrimination. Numerical results show that, using polarization diversity, improvements for the considered system performance can be realized with significantly lower SNR, despite a certain level of correlation and power unbalance between the diversity branches. In that manner, compared to the system with no diversity, the total needed transmit power for achieving the same level of system performances is reduced, and thus more energy efficient communication is enabled.  相似文献   
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