Preparation of barium hexaferrite by a hydrothermal method: structure and magnetic properties

Barium hexaferrite, BaFe¹²O₁₉, was obtained in hydrothermal conditions from a water suspension of -FeOOH and Ba(OH)₂ · 8H₂O at a temperature about 315° C. X-ray and Mössbauer spectroscopy as well as electron microscopy investigations demonstrated the appearance of -Fe₂O₃ as an intermediate phase in the hydrothermal process. The magnetic characteristics of the obtained isotropic magnets are the following: coercive fieldH _c 159 kA m^–1, residual inductionB _r 0.26 T, maximum energy product (BH) _max12 kJ m^–3. The hydrothermal procedure for the preparation of barium hexaferrite in comparison with the conventional one is discussed.     

智能定位的账单营销

营销商很早就意识到．具有同样文化背景，行为方式以及认识观念的人们彼此之间会自然地相互吸引，形成一个同类群体。一旦被定位到某个群体．人们会自然地模仿周围的人——进而形成同样的社会价值观、同样的品味和社会期望值。更重要的是．他们对产品、服务、媒体以及促销品具有相似的消费行为。我们可以根据人们这种相似的行为方式开发各种系统．这些系统可以根据人们最基本的社会经济地位和人口组成把他们及其家庭成员划归为不同的群体或组织。     

Catecholaminergic region A15 in the bovine and porcine hypothalamus

Magnocellular perikarya within the retrochiasmatic division of the supraoptic nucleus of bovine and porcine hypothalami were immunoreactive (ir) with antiserum against tyrosine hydroxylase (TH), but not dopamine-beta-hydroxylase (DBH). Few cells in this region were also immunoreactive for vasopressin (VP) or oxytocin (OT). In contrast, the main division of the supraoptic nucleus contained numerous perikarya immunoreactive for VP and OT, but not TH nor DBH. Both the retrochiasmatic and principal divisions of the supraoptic nuclei contained TH- and DBH-ir fibers and varicosities. This region in bovine and porcine hypothalami corresponds to the ventral A15 catecholaminergic (dopamine-producing) cell group.     

Procedural learning in first episode schizophrenia investigated with functional magnetic resonance imaging.

Objective: The present investigation assessed the severity, course, and cerebral implications of serial reaction time (SRT) procedural learning deficits in schizophrenia. Method: Hemodynamic changes on fMRI were assessed during an SRT task in 17 unmedicated first episode psychosis (FEP) patients and matched healthy controls. Results: The groups demonstrated comparable procedural learning and associated activation of anterior cingulate cortex, subcortical structures, and many left frontal structures. The groups also demonstrated comparable increased activation of right parietal structures on trials with demands for spatial localization without procedural memory. Relative to healthy controls, the schizophrenia sample showed less activation of one region of the left middle frontal cortex and more activation of left superior temporal cortex on procedural trials, but more activation of right medial frontal cortex on localization trials. Conclusions: Intact SRT procedural learning and normal or enhanced hemodynamic response in subcortical and right cortical structures diverges from prior results with medicated samples, suggesting a more focal cerebral dysfunction in the left middle frontal cortex before the onset of treatment. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Impact of the Dairy Matrix Structure on Milk Protein Digestion Kinetics: Mechanistic Modelling Based on Mini-pig In Vivo Data

Beyond the individual content in nutrients, it is now established that the matrix structure is also to consider when evaluating the nutritional properties and possible health effects of a food material. The objective of this study was to gain knowledge on the effect of the structure of dairy products on the digestion of milk proteins as inferred from a mathematical modelling of mini-pig in vivo data. Six dairy matrices of the same composition but differing by their physicochemical and structural properties were investigated. They were manufactured using technological processes commonly used in the industry (heat treatment, rennet gelation, acid gelation and mixing). The experimental results cover a 7-h postprandial period and consist of plasmatic amino acid concentrations as well as dry matter contents and chromium concentrations (a marker of the liquid phase of the meal) of samples collected at the stomach exit. The model developed not only accounts for the main digestive events but also for phenomena that can occur within the stomach (milk clotting and aggregate syneresis). It provides a good fitting of all the experimental data and allows estimating parameter values that can be explained by considering the properties of the matrices investigated. The model has also been used to estimate quantities that cannot be observed experimentally (stomach volumes, endogenous secretions, gastric emptying half-time, etc.) in order to recover a better picture of all the results and validate the model predictions against the literature. It even appears that our simulations of gastric emptying and aminoacidemia superimpose very well with previously published data obtained using similar matrices and the same mini-pig species. This study shows that the great differences in the kinetics of amino acid absorption that were observed experimentally can be fully understood by considering the behaviour of the dairy matrices within the stomach. It therefore offers interesting perspectives for the integration of food structure parameters, and more particularly for dairy products, in the comprehensive view of the nutritional quality of food products.