672 research outputs found
Columna deportiva: artículos sobre deporte, ética y sociedad
Este libro es una colección de artículos publicados originalmente en diversos periódicos y revistas durante los últimos quince años en los que indagamos sobre varios aspectos inquietantes de la locura deportiva.https://digitalcommons.brockport.edu/sunybeb/1000/thumbnail.jp
Partial protective effect of CCR5-Delta 32 heterozygosity in a cohort of heterosexual Italian HIV-1 exposed uninfected individuals
Despite multiple sexual exposure to HIV-1 virus, some individuals remain HIV-1 seronegative (exposed seronegative, ESN). The mechanisms underlying this resistance remain still unclear, although a multifactorial pathogenesis can be hypothesised. Although several genetic factors have been related to HIV-1 resistance, the homozigosity for a mutation in CCR5 gene (the 32 bp deletion, i.e. CCR5-Delta32 allele) is presently considered the most relevant one. In the present study we analysed the genotype at CCR5 locus of 30 Italian ESN individuals (case group) who referred multiple unprotected heterosexual intercourse with HIV-1 seropositive partner(s), for at least two years. One hundred and twenty HIV-1 infected patients and 120 individuals representative of the general population were included as control groups. Twenty percent of ESN individuals had heterozygous CCR5-Delta 32 genotype, compared to 7.5% of HIV-1 seropositive and 10% of individuals from the general population, respectively. None of the analysed individuals had CCR5-Delta 32 homozygous genotype. Sequence analysis of the entire open reading frame of CCR5 was performed in all ESN subjects and no polymorphisms or mutations were identified. Moreover, we determined the distribution of C77G variant in CD45 gene, which has been previously related to HIV-1 infection susceptibility. The frequency of the C77G variant showed no significant difference between ESN subjects and the two control groups. In conclusion, our data show a significantly higher frequency of CCR5-Delta 32 heterozygous genotype (p = 0.04) among the Italian heterosexual ESN individuals compared to HIV-1 seropositive patients, suggesting a partial protective role of CCR5-Delta 32 heterozygosity in this cohort
The peculiar structural features of kiwi fruit pectin methylesterase: amino acid sequence, oligosaccharides structure, and modeling of the interaction with its natural proteinaceous inhibitor
Pectin methylesterase (PME) from kiwi fruit (Actinidia deliciosa) is a glycoprotein, showing an apparent molecular mass of 50 kDa upon size exclusion chromatography and SDS-PAGE. The primary structure, elucidated by direct sequencing of the protein, comprises 321 amino acid residues providing a molecular mass of 35 kDa. The protein has an acetylated Thr residue at the amino terminus and five N-glycosylation consensus sequences, four of which are actually glycosylated. A careful investigation of the oligosaccharide structures demonstrated that PME glycans belong to complex type oligosaccharides essentially consisting of xylosylated polyfucosylated biantennary structures. Alignment with known mature plant PME sequences indicates that the postulated active site residues are conserved. Kiwi PME activity is inhibited following the interaction with the proteinaceous inhibitor PMEI, isolated from the same source. Gel-filtration experiments show that kiwi PME/PMEI complex is stable in a large pH range and dissociates only at pH 10.0. Modeling of the interaction with the inhibitor was performed by using the crystal structure of the complex between kiwi PMEI and tomato PME as a template. The model shows that the binding site is the same reported for tomato PME. However, additional salt link interactions are found to connect the external loops of kiwi PME to PMEI. This finding may explain the higher pH stability of the complex formed by the two kiwi proteins respect to that formed by PMEI and tomato PME
Impact of the polarization mode dispersion on a field demonstration of 40 Gbit/s soliton transmission over 500 km
Impact of polarisation mode dispersion infield demonstration of 40Gbit/s solitontransmission over 500 km
40Gbitis single-wavelength altemate-polarisation soliton
transmission over 5 0 0 h has been successfully demonstrated in a
field trial using dispersion-shifted fibre. Comparisons with an
equivalent laboratory trial and numerial simulations show that
the main source of impairment is polarisation mode dispersion
Manipulation and removal of defects in spontaneous optical patterns
Defects play an important role in a number of fields dealing with ordered
structures. They are often described in terms of their topology, mutual
interaction and their statistical characteristics. We demonstrate theoretically
and experimentally the possibility of an active manipulation and removal of
defects. We focus on the spontaneous formation of two-dimensional spatial
structures in a nonlinear optical system, a liquid crystal light valve under
single optical feedback. With increasing distance from threshold, the
spontaneously formed hexagonal pattern becomes disordered and contains several
defects. A scheme based on Fourier filtering allows us to remove defects and to
restore spatial order. Starting without control, the controlled area is
progressively expanded, such that defects are swept out of the active area.Comment: 4 pages, 4 figure
Lipid profile during pregnancy in HIV-infected women
Purpose: We investigated the evolution of serum lipid levels in HIV-infected pregnant women and the potential effect of antiretroviral treatment during pregnancy using data from a national surveillance study. Method: Fasting lipid measurements collected during routine care in pregnancy were used, analyzing longitudinal changes and differences in lipid values at each trimester by protease inhibitors (Pls) and stavudine use. Multivariate analyses were used to control for simultaneous factors potentially leading to hyperlipidemia. Study population included 248 women. Results: Lipid values increased progressively and significantly during pregnancy: mean increases between the first and third trimesters were 141.6 mg/dL for triglycerides (p <.001), 60.8 mg/dL for total cholesterol (p <.001), 13.7 mg/dL for HDL cholesterol (p <.001), and 17.8 mg/dL for LDL cholesterol (p =.001). At all trimesters, women on PIs had significantly higher triglyceride values compared to women not on Pis. The effect of Pls on cholesterol levels was less consistent. Stavudine showed a dyslipidemic effect at first trimester only. Multivariate analyses confirmed these observations and suggested a potential role of other cofactors in the development of hyperlipidemia during pregnancy. Conclusion: The changes observed point to the need to further explore the causes and the clinical correlates of hyperlipidemia during pregnancy in women with HIV
Use of particle counter system for the optimization of sampling ,identification and decontamination procedures for biological aerosols dispersion in confined environment
Abstract
In a CBRNe (Chemical, Biological, Radiological, Nuclear and explosive) scenario, biological agents hardly allow
efficient detection/identification because of the incubation time that provides a lag in symptoms outbreak following
their dissemination. The detection of atmospheric dispersion of biological agents (i.e.: toxins, viruses, bacteria and so
on) is a key issue for the safety of people and security of environment. Another fundamental aspect is related to the
efficiency of the sampling method, which leads to the identification of the agent released, in fact an effective sampling
method is needed either to identify the contamination and to check for the decontamination procedure.
Environmental monitoring is one of the ways to improve fast detection of biological agents; for instance, particle
counters with the ability of discriminating between biological and non-biological particles are used for a first warning
when the amount of biological particles exceeds a particular threshold. Nevertheless, these systems are not able to
distinguish between pathogen and non-pathogen organisms, thus, classical “laboratory” assays are still required to
unambiguously identify the particle which triggered the warning signal. In this work, a combination of commercially
available equipment for detection and identification of the atmospheric dispersion of biological agents was evaluated in
partnership between the Italian Army, the Department of Industrial Engineering and the School of Medicine and
Surgery of the University of Rome “Tor Vergata”. The aim of this work, whose results are presented here, was to
conduce preliminary studies on the dynamics of biological aerosols fallout after its dispersion, to improve detection,
sampling and identification techniques. This will help minimizing the impact of the release of biological agents,
guarantee environmental, and people safety and securit
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