3,465 research outputs found
Engineering partial resistance to cucumber mosaic virus in tobacco using intrabodies specific for the viral polymerase
A rapid and simple uhplc-ms/ms method for quantification of plasma globotriaosylsphingosine (Lyso-gb3)
Fabry disease (FD) is a rare X-linked lysosomal storage disorder caused by α-galactosidase A gene (GLA) mutations, resulting in loss of activity of the lysosomal hydrolase, α-galactosidase A (α-Gal A). As a result, the main glycosphingolipid substrates, globotriaosylceramide (Gb3) and globotriaosylsphingosine (lyso-Gb3), accumulate in plasma, urine, and tissues. Here, we propose a simple, fast, and sensitive method for plasma quantification of lyso-Gb3, the most promising secondary screening target for FD. Assisted protein precipitation with methanol using Phree cartridges was performed as sample pre-treatment and plasma concentrations were measured using UHPLC-MS/MS operating in MRM positive electrospray ionization. Method validation provided ex-cellent results for the whole calibration range (0.25–100 ng/mL). Intra-assay and inter-assay accuracy and precision (CV%) were calculated as <10%. The method was successfully applied to 55 plasma samples obtained from 34 patients with FD, 5 individuals carrying non-relevant polymorphisms of the GLA gene, and 16 healthy controls. Plasma lyso-Gb3 concentrations were larger in both male and female FD groups compared to healthy subjects (p < 0.001). Normal levels of plasma lyso-Gb3 were observed for patients carrying non-relevant mutations of the GLA gene compared to the control group (p = 0.141). Dropping the lower limit of quantification (LLOQ) to 0.25 ng/mL allowed us to set the optimal plasma lyso-Gb3 cut-off value between FD patients and healthy controls at 0.6 ng/mL, with a sensitivity of 97.1%, specificity of 100%, and accuracy of 0.998 expressed by the area under the ROC curve (C.I. 0.992 to 1.000, p-value < 0.001). Based on the results obtained, this method can be a reliable tool for early phenotypic assignment, assessing diagnoses in patients with borderline GalA activity, and confirming non-relevant mutations of the GLA gene
Antioxidant properties of humic acids extracted from saltmarsh soils (Marano and Grado Lagoon, northern Adriatic Sea)
Characterization of humic fractions in leachates from soil under organic and conventional management and their interactions with the root zone
Humic fractions were shown to be closely involved in gene expression
and promotion of different PM H+-ATPase isoforms, as well as in lateral root
development, indicating an enhanced nutrient absorption capacity of the plant
root system. HPLC-SEC confirmed that water-soluble humic substances (WSHS)
correspond to a subfraction of the fulvic fraction of humic substances. This was
supported by E465/E665 ratios higher than 8.5. These ratios generally increased over
the growing season in cultivated soils but showed significant differences between
conventionally and organically managed bare soils. FTIR data and the analytical
quantification of carboxyls confirmed relevant structural changes in bare soil under
both organic and conventional farming management. Absorption intensities ratios
at 1,590\u20131,570 cm-1 and 1,440\u20131,380 cm-1 showed the predominant aliphatic
character of these molecules
Characterization of humic fractions in leachates from soil under organic and conventional management and their interactions with the root zone
Humic fractions were shown to be closely involved in gene expression
and promotion of different PM H+-ATPase isoforms, as well as in lateral root
development, indicating an enhanced nutrient absorption capacity of the plant
root system. HPLC-SEC confirmed that water-soluble humic substances (WSHS)
correspond to a subfraction of the fulvic fraction of humic substances. This was
supported by E465/E665 ratios higher than 8.5. These ratios generally increased over
the growing season in cultivated soils but showed significant differences between
conventionally and organically managed bare soils. FTIR data and the analytical
quantification of carboxyls confirmed relevant structural changes in bare soil under
both organic and conventional farming management. Absorption intensities ratios
at 1,590–1,570 cm-1 and 1,440–1,380 cm-1 showed the predominant aliphatic
character of these molecules
The AMS-02 Time of Flight System. Final Design
The AMS-02 detector is a superconducting magnetic spectrometer that will
operate on the International Space Station. The time of flight (TOF) system of
AMS-02 is composed by four scintillator planes with 8, 8, 10, 8 counters each,
read at both ends by a total of 144 phototubes. This paper describes the new
design, the expected performances, and shows preliminary results of the ion
beam test carried on at CERN on October 2002.Comment: 4 pages, 6 EPS figures. Proc. of the 28th ICRC (2003
On the electromagnetic energy resolution of Cherenkov-fiber calorimeters
Electromagnetic calorimeters which sample the Cherenkov radiation of shower particles in optical fibers operate in a markedly different manner from calorimeters which rely on the dE/dx of shower particles. The well-understood physics of electromagnetic shower development is applied to the case of Cherenkov-fiber calorimetry (also known as quartz fiber calorimetry) and the results of systematically performed studies are considered in detail to derive an understanding of the critical parameters involved in energy measurement using such calorimeters. A quantitative parameterization of Cherenkov-fiber calorimetry electromagnetic energy resolution is proposed and compared with existing experimental results
The TOF counters of the AMS-02 experiment: space qualification tests and beam test results
The scintillator counters of the TOF system of AMS-02 is beeing constructed to match the needs of the AMS-02 experiment that is armed by a high aperture superconducting dipole magnet. The goals of the TOF-02 hodoscopes actually are: to give the fast trigger to the all sub-detectors of AMS-02; to measure the particle velocity ensuring a 1 Ă— 10 9 albedo rejection; to measure the absolute charge by particle energy loss, up to at least Z = 20 . In spring of 2005 all the TOF counter planes will be assembled and the space qualification tests will be performed. A description of the first test results and of the TOF performances will be given
Study of single muons with the Large Volume Detector at Gran Sasso Laboratory
The present study is based on the sample of about 3 mln single muons observed
by LVD at underground Gran Sasso Laboratory during 36500 live hours from June
1992 to February 1998. We have measured the muon intensity at slant depths from
3 km w.e. to 20 km w.e. Most events are high energy downward muons produced by
meson decay in the atmosphere. The analysis of these muons has revealed the
power index of pion and kaon spectrum: 2.76 \pm 0.05. The reminders are
horizontal muons produced by the neutrino interactions in the rock surrounding
LVD. The value of this flux is obtained. The results are compared with Monte
Carlo simulations and the world data.Comment: 13 pages, 2 figures, accepted for publication in "Physics of Atomic
Nuclei
An assay for secologanin in plant tissues based on enzymatic conversion into strictosidine
The secoiridoid glucoside secologanin is the terpenoid building block in the biosynthesis of terpenoid indole
alkaloids. A method for its determination in plant tissues and in cell suspension cultures has been developed.
This assay is based on the condensation of secologanin with tryptamine, yielding strictosidine, in a reaction
catalysed by the enzyme strictosidine synthase (STR; E.C. 4.3.3.2). Subsequently, the formation of
strictosidine is quantified by high performance liquid chromatography (HPLC). STR was isolated from
transgenic Nicotiana tabacum cells expressing a cDNA-derived gene coding for STR from Catharanthus
roseus. The high specificity of STR for secologanin, in combination with a sensitive and selective HPLC
system, allows a simple extraction of secologanin from plant tissue. The detection limit of this method is
15 ng secologanin. Using this assay, secologanin contents were determined in tissues of various plant species;
Lonicera xylosteum hairy roots were found to contain 1% of secologanin on a dry weight basis. # 1998 John
Wiley & Sons, Ltd.info:eu-repo/semantics/publishedVersio
- …