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11.
Taste perception is one of the senses crucial for many organisms. There are five basic tastes, i.e., sweet, bitter, salty, sour, and umami, and it is suggested that the taste of fat should be included in this list. This paper reviews the current state of knowledge about the involvement of G protein coupled receptors (GPCRs) in taste sensing and intracellular signaling. GPCR receptors are focal point of interest for pharmaceutical industry. However, their ability to interact with a variety of taste substances makes these receptors interesting target for food and nutrient companies.  相似文献   
12.
This article is based on a review of literature devoted to the phenomenon of SDE via achiral chromatography since the appearance of the seminal work of Professor Emanuel Gil-Av. The discussed examples of chromatographic studies are related to amides derived from chiral amines and α- and β-amino acids. We discuss the observed SDE magnitude as a function of a compound's structure, and composition of eluent and stationary phases, providing some mechanistic considerations. Particular emphasis is given to the aspect of SDE via achiral chromatography as an emerging unconventional enantiomeric purification technique.  相似文献   
13.
In this paper a general solution to the path following problem for mobile manipulators with non-holonomic mobile platform has been presented. New proposed control algorithms — for mobile manipulators with fully known dynamics or with parametric uncertainty in the dynamics — take into considerations the kinematics as well as the dynamics of the non-holonomic mobile manipulator. The convergence of the control algorithms is proved using the LaSalle's invariance principle.  相似文献   
14.
Multiple sclerosis (MS) is a chronic inflammatory demyelinating and neurodegenerative disease of the central nervous system (CNS) with unknown etiology. It was recently suggested that autoimmunity, which had long been considered to be destructive in MS, might also play a protective role in the CNS of MS patients. Neurotrophins are polypeptides belonging to the neurotrophic factor family. While neurotrophins mediate cell survival and proliferation in the nervous system, they are also expressed within peripheral blood mononuclear cells fraction (PBMCs) of immunological system. In MS additional neurotrophic support from PBMCs might compensate relative neurotrophins deficiency in the damaged CNS tissue that needs to be repaired. Failure to produce the adequate neurotrophins concentrations might result in decreased protection of the CNS, consequently leading to increased atrophy, which is the main determinant of MS patients’ end-point disability. There are several lines of evidence, both from clinical research and animal models, suggesting that neurotrophins play a pivotal role in neuroprotective and neuroregenerative processes that are often defective in the course of MS. It seems that neuroprotective strategies might be used as potentially valuable add-on therapies, alongside traditional immunomodulatory treatment in multiple sclerosis.  相似文献   
15.
16.
Single-crystal stable-temperature (ST)-cut quartz substrates, which have a (0 1 1 1) crystallographic plane with their surface normal lying close to 38° from the y axis ([0 1 0]), were annealed in air prior to use as a support for aligned carbon nanotube growth by chemical vapor deposition. Very smooth substrate surfaces were obtained with annealing times in the vicinity of 15 h at a temperature of 750 °C. These smooth surfaces are ideal for the growth of horizontally aligned SWCNTs with high spatial density, while less dense SWCNTs were obtained with less smooth surfaces. Under optimized growth conditions, only SWCNT are observed and they can grow to lengths in excess of 100 μm. Our findings suggest structural defects interfere with the growth process. A binary Fe/Co catalyst was employed to grow the nanotubes. No obvious dependence on the Fe:Co ratio is observed.  相似文献   
17.
Eight species of Rutaceae or Umbelliferae, known to cause or suspected of causing photophytodermatitis, had the linear furanocoumarins psoralen, bergapten, and xanthotoxin on their leaf surfaces, in concentrations varying from 0.014 to 1800 /gmg/g fresh weight, equivalent to 0.17–56% of the total leaf concentration. The higher percentage generally observed for spring leaves compared to autumn leaves suggests a higher rate of transfer of these furanocoumarins to the surface in the younger leaves. Among the plants studied,Ruta graveolens had the highest surface concentrations of all three furanocoumarins. The relatively high effectiveness in causing dermatitis of some species with low surface concentrations may be explained by a more effective mechanism of transfer of the furanocoumarins to the skin. A role in the defense of the plant is suggested by their accumulation on the plant surface.A paper based on the work reported here was presented at the Groupe Polyphénols conference, Brock University, St. Catharines, Ontario, Canada, August 19–19, 1988.  相似文献   
18.
Development rates vary among individuals, often as a result of direct competition for food. Survival of young might depend on their learning abilities, but it remains unclear whether learning abilities are affected by nutrition during development. The authors demonstrated that compared with controls, 1-year-old Western scrub jays (Aphelocoma californica) that experienced nutritional deficits during early posthatching development had smaller hippocampi with fewer neurons and performed worse in a cache recovery task and in a spatial version of an associative learning task. In contrast, performance of nutritionally deprived birds was similar to that of controls in 2 color versions of an associative learning task. These findings suggest that nutritional deficits during early development have long-term consequences for hippocampal structure and spatial memory, which, in turn, are likely to have a strong impact on animals' future fitness (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
19.
Poland is a country where power and heat energy production is based on conventional fuel combustion, above all hard coal and lignite. In power plants and combined heat and power plants, fossil fuel combustion results in emitting to the atmosphere first of all SO2, NOx, CO, particulate matter, greenhouse gases for instance N2O and CO2. For many years the Polish power industry has tried to reduce the emission of air contaminants to the atmosphere. The reduction is feasible on account of various methods of emission reduction, which have been advanced and applied for many years.

The paper presents conventional fuels used in the Polish professional power industry, as well as the principal emission types occurring there for the last 10 years and the undertaken reduction measures.  相似文献   

20.
It was proposed to classify semiconductor devices into groups of differentiated quality on the basis of their low-frequency noise. The methodology of semiconductor device classification taking into account results of noise investigations of two biased samples was presented.  相似文献   
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