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Excessive energy intake may evoke complex biochemical processes characterized by inflammation, oxidative stress, and impairment of mitochondrial function that represent the main factors underlying noncommunicable diseases. Because cow milk is widely used for human nutrition and in food industry processing, the nutritional quality of milk is of special interest with respect to human health. In our study, we analyzed milk produced by dairy cows fed a diet characterized by a high forage:concentrate ratio (high forage milk, HFM). In view of the low n-6:n-3 ratio and high content of conjugated linoleic acid of HFM, we studied the effects of this milk on lipid metabolism, inflammation, mitochondrial function, and oxidative stress in a rat model. To this end, we supplemented for 4 wk the diet of male Wistar rats with HFM and with an isocaloric amount (82 kJ, 22 mL/d) of milk obtained from cows fed a diet with low forage:concentrate ratio, and analyzed the metabolic parameters of the animals. Our results indicate that HFM may positively affect lipid metabolism, leptin:adiponectin ratio, inflammation, mitochondrial function, and oxidative stress, providing the first evidence of the beneficial effects of HFM on rat metabolism.  相似文献   
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A cross-sectional study was performed to obtain risk factors for hepatitis B disease, HBsAg carriers and immunised personnel, among 2470 workers in a general hospital in Madrid, Spain. The data obtained were analyzed with multiple logistic regression to obtain beta coefficients for variables. The results of the analysis show that being a nurse or being regularly exposed to blood are the most important risk factors for hepatitis B acquisition. The length of time working at the same job activity was also a risk factor. The resulting beta coefficients allow the construction for a hepatitis non-immunised, HBsAg carrier and immunised HBV status, which can select subjects for a hepatitis B vaccination program.  相似文献   
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The pulse-stream technique, which represents neural states as sequences of pulses, is reviewed. Several general issues are raised, and generic methods appraised, for pulsed encoding, arithmetic, and intercommunication schemes. Two contrasting synapse designs are presented and compared. The first is based on a fully analog computational form in which the only digital component is the signaling mechanism itself-asynchronous, pulse-rate encoded digital voltage pulses. In this circuit, multiplication occurs in the voltage/current domain. The second design uses more conventional digital memory for weight storage, with synapse circuits based on pulse stretching. Integrated circuits implementing up to 15000 analog, fully programmable synaptic connections are described. A demonstrator project is described in which a small robot localization network is implemented using asynchronous, analog, pulse-stream devices.  相似文献   
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In this paper two problems on the class of k -trees, a subclass of the class of chordal graphs, are considered: the fast reordering problem and the isomorphism problem. An O(log 2 n) time parallel algorithm for the fast reordering problem is described that uses O(nk(n-k)/\kern -1ptlog n) processors on a CRCW PRAM proving membership in the class NC for fixed k . An O(nk(k+1)!) time sequential algorithm for the isomorphism problem is obtained representing an improvement over the O(n 2 k(k+1)!) algorithm of Sekharan (the second author) [10]. A parallel version of this sequential algorithm is presented that runs in O(log 2 n) time using O((nk((k+1)!+n-k))/log n) processors improving on a parallel algorithm of Sekharan for the isomorphism problem [10]. Both the sequential and parallel algorithms use a concept introduced in this paper called the kernel of a k -tree.  相似文献   
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Biodegradable hollow microfibres containing particles loaded with specific active agents can be potentially employed to produce a special kind of substrate for tissue engineering, able to function as a scaffold and at the same time to act as a drug‐releasing system. Biodegradable hollow microfibres based on poly(lactic acid) were produced by a dry–wet spinning procedure. Drug‐loaded microparticles were prepared by a simple oil‐in‐water emulsion and entrapped inside the fibres. The morphology of both fibres and particles was investigated by scanning electron microscopy. The mechanical and thermal properties of the fibres were investigated by tensile tests and differential scanning calorimetry. In vitro tests were performed to evaluate the release of the drug from the fibres loaded with the particles Copyright © 2004 Society of Chemical Industry  相似文献   
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We hypothesized that hydrocephalus can cause death of brain cells and that generation of new brain cells might compensate for the cell loss. Hydrocephalus was induced in 3-week-old rats by injection of kaolin into the cisterna magna. The brains were studied 1 to 4 weeks later by histochemical, immunochemical, and ultrastructural methods. The ventricles enlarged progressively. Some axons in the corpus callosum were injured as early as 1 week, but axonal damage was not prevalent until 4 weeks when ventriculomegaly became severe. Dying cells detected by DNA end labeling and often identified as oligodendrocytes by electron microscopy were evident in white matter. Late-stage hydrocephalus was associated with a significant increase in the quantity of dying cells. Hydrocephalus was associated with increased Ki67 labeling and bromodeoxyuridine incorporation in the subependymal zone. Reactive changes were identified among astrocytes, oligodendroglia, and microglia. We conclude that hydrocephalus causes, in addition to axonal injury, gradual cell death in the cerebrum, particularly the white matter. The brain response includes production of new glial cells, but whether the new cells play any beneficial role remains unknown.  相似文献   
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The lack of sufficient suitable human donor lungs for the many patients requiring pulmonary transplantation as life-saving therapy for end-stage lung diseases has generated extensive interest in cross-species lung transplantation. Ethical concerns and those of animal rights advocates have prompted studies of nonprimate species as potential solid organ donors for humans. This paper provides an overview of some of the laboratory studies of cross-species pulmonary transplantation performed over the past 20 years and focuses, in particular, on more recent work (from our laboratory and others) in the area of porcine-to-primate pulmonary xenotransplantation.  相似文献   
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