Natural medicinal products have been used for millennia for the treatment of several ailments. Although many have been superseded by conventional pharmaceutical approaches, there is currently a ...resurgence in the interest in natural products by the general public and the use of complementary and alternative medicine is increasing rapidly in developed countries. Also, pharmaceutical industries are more and more interested in examining their potential as sources of novel medicinal compounds which may act as growth factor or show immunomodulatory or anti-microbial activity. The subgroup of natural bioactive compounds that bridge the gap between food products and drugs are termed nutraceuticals or functional foods. In contrast with most standard medicinal compounds, nutraceuticals are generally used to prevent rather than to treat disease. Many of the claims for such products are supported by very limited scientific evidence. However, there has recently been a great interest at evaluating the mechanism by which natural products exert their beneficial effects in the gastrointestinal tract. In particular, a major area of interest is for the use of biologically active chemical components of plants, i.e. phytochemicals, in a number of gastrointestinal disorders. While the major focus of phytochemical research has been on cancer prevention, several products of plant origin are being used and/or under study for a variety of other gastrointestinal problems. In this review we discuss the scientific evidence supporting the potential use of nutraceuticals as agents capable to prevent or accelerate healing of gastrointestinal mucosal damage, with a focus on polyphenol extracts obtained from apple.
Water stress is an increasing environmental constraint affecting tomato growth and yield in Mediterranean areas. Solanum pennellii is a wild tomato species that exhibits a higher water use efficiency ...compared with cultivated S. lycopersicum. In particular, a cultivated line carrying a small S. pennellii region on chromosome 9 (IL 9-2-5) was identified as more tolerant to water deficit. In this work, the tolerant (IL 9-2-5) and the susceptible (M82) genotypes were subjected to three different water regimes: irrigation with 100% (V1), 50% (V2) and 25% (V3) field capacity. To evaluate the physiological response of IL 9-2-5 and M82 to water deficit, leaf functional traits, plant biomass production and maximal PSII photochemical efficiency were measured together with photosynthetic pigments and phenolic compounds. The higher tolerance to water deficiency of IL 9-2-5 was associated with the development of a better antioxidant system, especially in treatment V3. In addition, IL 9-2-5 had higher values of sclerophylly and leaf dry matter content thus confirming that the tolerance of IL 9-2-5 can be attributed to traits related to leaf morphology and physiology. In future, identification of polymorphisms in key-genes controlling these traits can guide breeding efforts aimed at improving susceptible genotypes.
For the identification of particles in the momentum range 0.5–2.5GeV/c, the ALICE experiment uses a Time Of Flight array consisting of Multigap Resistive Plate Chambers (MRPC) in the form of long ...strips. The design of the detector elements is as follows : double stack MRPCs with glass resistive plates and 5 gas gaps of 250μm per stack. The latest results on the performance of these MRPCs are presented. Typical values of time resolution σ are better than 50ps, with an efficiency of 99.9% and a long, more than 1.5kV, streamer-free plateau.
We present in this paper a study of the Alice-TOF Multigap Resistive Plate Chamber (MRPC) performance by using several gas mixtures. We also present a search for possible ageing effects, by studying ...two MRPCs irradiated at the CERN Gamma Irradiation Facility.
AbstractThe ALICE TOF array will be built using the Multigap Resistive Plate Chamber(MRPC) configured as a double stack. Each stack contains 5 gas gaps with width of 250 μm. There has been an intense ...R&D effort to optimise this new detector to withstand the problems connected with the high level of radiation at the LHC. One clear outcome of the R&D is that the growth of the gas avalanche is strongly affected by space charge. The effect of the space charge is a decrease in the rate of change in gain with electric field; this allows more stable operation of this detector. We have measured the gain as a function of the electric field and also measured the ratio of the fast charge to the total charge produced in the gas gap. It is well established that RPCs built with 250 μm gas gap have a much superior performance than 2 mm gaps; we discuss and compare the performance of 250 μm gap MRPCs with 2 mm gap RPCs to show the importance of space-charge limitation of avalanche growth.PACS: 29.40.Cs – 7.77.-n – 52.80.Dy
Scintillation tiles with MRS APD light readout (START) are proposed to be used as basic triggering units of a cosmic muon facility intended for regular tests of all of the numerous ALICE TOF modules ...in the course of their mass production and exploitation. A prototype 32-channel array of STARTs has been assembled and tested with cosmic rays and beam. With the bias voltage at approximately 50
V, the system has shown operational consistency and homogeneity, almost 100% detection efficiency over the whole surface and intrinsic noise of
10
-
2
Hz
per detecting unit. If STARTs are to be mass-produced, the cost of a mosaic array is estimated at a moderate level of 3–
4
kUSD
/
m
2
.
Inhibitory interneurons often generate synchronous activity as an emergent property of their interconnections. To determine the role of electrical synapses in such activity, we constructed mice ...expressing histochemical reporters in place of the gap junction protein Cx36. Localization of the reporter with somatostatin and parvalbumin suggested that Cx36 was expressed largely by interneurons. Electrical synapses were common among cortical interneurons in controls but were nearly absent in knockouts. A metabotropic glutamate receptor agonist excited LTS interneurons, generating rhythmic inhibitory potentials in surrounding neurons of both wild-type and knockout animals. However, the synchrony of these rhythms was weaker and more spatially restricted in the knockout. We conclude that electrical synapses containing Cx36 are critical for the generation of widespread, synchronous inhibitory activity.
We have investigated the operation of the Multigap Resistive Plate Chamber (MRPC) for the ALICE-TOF system with a gas mixture free of flammable components. Two different gas mixtures, with and ...without iso-C4H10have been used to measure the performance of the MRPC. The efficiency, time resolution, total charge, and the fast to total charge ratio have been found to be comparable.
We have investigated the operation of the multigap resistive plate chamber (MRPC) for the ALICE-TOF system with a gas mixture free of flammable components. Two different gas mixtures, with and ...without iso-C
4H
10 have been used to measure the performance of the MRPC. The efficiency, time resolution, total charge, and the fast to total charge ratio have been found to be comparable.
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