Nutraceutical plants provide nutrients for the animal as well as secondary compounds that can affect the biology and survival of gastrointestinal nematodes (GIN). Current screening of nutraceutical ...plants is based on in vitro evidence of anthelmintic (AH) activity against different life stages of GIN, but nutritional information is omitted or scarce. This study proposes an integral in vitro screening protocol to identify the nutraceutical value of the foliage from plant species consumed by small ruminants, using
Haemonchus contortus
as a biological model. The leaves from
Acacia collinsii
,
A
.
pennatula
,
Bunchosia swartziana
,
Gymnopodium floribundum
,
Havardia albicans
,
Leucaena leucocephala
,
Lysiloma latisiliquum
,
Mimosa bahamensis
,
Piscidia piscipula
, and
Senegalia gaumeri
were evaluated for their chemical composition and in vitro digestibility. Acetone:water extracts (70:30) from leaves of each plant were evaluated using the egg hatch assay and larval exsheathment inhibition assay. Respective effective concentrations 50% (EC
50
) were determined for each assay. The ten plant species showed good nutritional value for ruminants, including crude protein (> 10%), metabolizable energy (> 2.9 MJ/kg DM), and varied CT content (from 1.0 to 37.6%). The best AH activity against
H
.
contortus
eggs (EC
50
= 401.8 μg/mL) and L
3
(EC
50
= 83.1 μg/mL) was observed for
S
.
gaumeri
extract. Although all the plant species showed in vitro nutraceutical potential, the leaves of
S
.
gaumeri
had the best values. The proposed in vitro protocol showed to be useful for the integral assessment of the nutraceutical potential of different plant species as it included the nutritional value and the AH activity against eggs and L
3
in the selected plant species.
Experimental ion mobility measurements for the LCTPC Collaboration Cortez, A.F.V.; Santos, M.A.G.; Veenhof, R. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
08/2019, Letnik:
936
Journal Article
Recenzirano
Measuring the mobility of ions in gases is relevant in several areas, from physics to chemistry, e.g. in gaseous radiation detectors modelling and in the understanding of the pulse shape formation. ...One of these examples is the upcoming LCTPC (Linear Collider TPC) for the International Linear Collider (ILC), where a gating device will be installed at a certain distance from the gas amplification stage to neutralize the ions produced. Knowing the ion mobility will allow to calculate this distance and to ensure a high ion reduction while minimizing the thickness of the end plate. This work focuses on measurements of positive ion mobility for mixtures of interest for the LCTPC, more specifically Ar-CF4-iC4H10 (95-3-2).
A
bstract
NEXT-100 is an electroluminescent high-pressure xenon gas time projection chamber that will search for the neutrinoless double beta (0
νββ
) decay of
136
Xe. The detector possesses two ...features of great value for 0
νββ
searches: energy resolution better than 1% FWHM at the
Q
value of
136
Xe and track reconstruction for the discrimination of signal and background events. This combination results in excellent sensitivity, as discussed in this paper. Material-screening measurements and a detailed Monte Carlo detector simulation predict a background rate for NEXT-100 of at most 4 × 10
−4
counts keV
−1
kg
−1
yr
−1
. Accordingly, the detector will reach a sensitivity to the 0
νββ
-decay half-life of 2.8 × 10
25
years (90% CL) for an exposure of 100 kg·year, or 6.0 × 10
25
years after a run of 3 effective years.
The primary scintillation signal in gaseous detectors can be used to obtain the initial interaction time of a detected event, but existing results in the literature for its yield in gaseous xenon are ...scarce and there is not a good agreement between them. In this work, a standard Gas Proportional Scintillation Counter (GPSC) was used to measure the absolute primary scintillation yield of gaseous xenon at 800 Torr for 5.9 keV X-rays, in order to try to clarify its value. The experimental determination was carried out using the ratio between the primary and secondary scintillation signals. The detection efficiencies of both signals were determined by Monte Carlo simulation results were used to correct the measured ratios. A primary scintillation yield of 73.4 ± 8.8 photons by 5.9 keV X-ray was obtained, from which a wp-value, i.e, the average energy necessary to produce a primary scintillation photon in xenon, of 80 ± 12 eV was obtained.
Also, in the same conditions, the primary scintillation was studied in Xenon-Trimethylamine (TMA – (CH3)3N), mixtures with TMA fraction between 0.1% and 1.0%. The primary scintillation signal was only observable at the lowest TMA fraction in the mixture (0.1%). For higher fractions, the primary scintillation signal was not observable, indicating that these may not be suitable mixtures for experiments that use the primary scintillation signal.
A new experimental system was recently developed to measure the mobility of both positive and negative ions: the Dual-Polarity Ion Drift Chamber (DP-IDC). In this work, we present a detailed ...description of the experimental setup and technique used, as well as the initial studies carried out. The reduced ion mobilities of SF5− and SF6− were measured in pure SF6, SF6-CF4 and SF6-N2, for pressures between 10 and 30 Torr and reduced electric fields ranging from 10 to 40 Td. The results were compared with experimental and theoretical data available, and a good performance was found. The study of the mobility of positive ions in Ne-CF4 gas mixtures was also performed, with the results obtained showing a good agreement with those determined in a similar setup previously developed by our group. The importance of this type of studies is also discussed, along with the future prospects for this experimental system.
A new experimental system was recently developed to measure the mobility of both positive and negative ions: the Dual-Polarity Ion Drift Chamber (DP-IDC). This system is intended to better understand ...the transport properties of ions in gases relevant for the performance of large volume gaseous detectors like the Negative Ion Time Projection Chambers (NITPCs). In this work, we present a description of the experimental setup and technique used, and the initial studies carried out in Xe–SF6 mixtures, whose interest has attracted attention as a possible alternative in searches for the neutrinoless double-beta decay.
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