687 research outputs found
Electron transfer in polyaromatic hydrocarbons and molecular carbon nanostructures
Planar and curved polycyclic aromatic hydrocarbons (PAHs)
represent an interesting class of compounds with physical
chemical properties particularly appealing, as good organic
semiconductors and molecular model of larger carbon nano-
structures. Investigation of the heterogeneous electron transfer
in these systems lets to probe their electronic properties and
the reactivity of the corresponding generated carbanions and
carbocations that can form new bonds, thus leading to different
carbon systems. A particular focus is on the intrinsically high
reactivity of carbocations which induces a series of reactions
building up new carbon–carbon bonds, thus allowing to
enlarge the initial molecular unit into a nanostructure. This
represents a new and convenient way to exploit the electro-
chemically triggered reactivity into the synthesis of carbon
nanostructured materials
Effectiveness of antihypertensive therapy in HIV-positive patients: evaluation to 144 weeks
Hypertension is more prevalent among HIV-infected subjects than in the general population, contributing to increased cardiovascular risk in HIV+ patients. The angiotensin II receptor blocker telmisartan is also a partial peroxisome proliferator activated receptor (PPAR)-γ agonist, with documented effects on improving hypertension, lipid metabolism and renal function. Therefore telmisartan was found to be the first choice for treatment of HIV+ hypertensive patients. Aim of this study was to evaluate the durability on 144 weeks of treatment with telmisartan in HIV+ patients. 13 HIV+ Caucasian male patients treated with combined antiretroviral therapy (cART) and discovered to be naïve hypertensive, were given 80 mg telmisartan daily. Systolic (SBP) and diastolic (DBP) blood pressure, viro-immunological, lipid and metabolic parameters, including triglycerides, cholesterol, insulin resistance (HOMA-IR), inflammatory markers, C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), indexes of renal function and cardiovascular risk, microalbuminuria, cystatin C, were measured at baseline (T0), and after 24 (T24), 48 (T48), 72 (T72), 96 (T96), 120 (T120) and 144 (T144) weeks. Treatment with telmisartan decreased SBP and DBP levels during the 144 weeks of observation. We also observed improved HDL-cholesterol, HOMA-IR, microalbuminuria and cystatin C at the end of study. Triglycerides and total cholesterol significantly decreased and HDL-cholesterol significantly increased. Total cholesterol/HDL cholesterol ratio improved significantly. Throughout in the course of the trial our patients showed a significant improvement of the percentage of CD4+ and CD8+. Eventually in all 144 weeks of therapy with telmisartan 80 mg/day have not observed adverse events or dropouts. Telmisartan was effective in improving hypertension, lipid metabolism and renal function in 144 weeks of evaluation. It determines the improvement of cystatin C and microalbuminuria, markers of renal function and cardiovascular risk. Telmisartan doesn't interfere with cART, not interfering with the recovery of immunological HIV patients. Telmisartan has confirmed durability and effectiveness, excellent tolerability and an high persistance with a good blood pressure control. Therefore telmisartan reveals the first choice in the treatment of hypertension in HIV+ because of significant morbidity in this group of patients
A retrospective study on the artificial mummification of the Blessed Andrea da Montereale (AD 1479)
Andrea da Montereale was a 15th Century Augustinian monk from the inner Abruzzo region, central Italy. We investigated the preservation mechanisms of his body by retrospective survey of textual sources and reports from the Canonical Recognitions. The partially mummified body of the Blessed Andrea da Montereale revealed indisputable evidence of artificial mummification (excerebration and evisceration cuts, absence of internal organs) at visual inspection. The cadaver features emphasized by the hagiographers (vivid colours, absence of putrefaction or bad smelling for thirty days after death, without balsams treatments) sounds like an unrequested explanation for the body miraculous preservation. To the best of our knowledge, this represents the twelfth known case of an embalmed body in Catholic Religion, the tenth in Central Italy, and the second one documented in the Abruzzo regio
Study of polarization observables in double pion photoproduction on the proton
Using a model for two pion photoproduction on the proton previously tested in
total cross sections and invariant mass distributions, we evaluate here
polarization observables on which recent experiments are providing new
information. We evaluate cross sections for spin 1/2 and 3/2, which are
measured at Mainz and play an important role in tests of the GHD sum rule.
We also evaluate the proton polarization asymmetry which is
currently under investigation at GRAAL in Grenoble.Comment: 23 pages, 14 ps figure
A spectroscopic and molecular dynamics study on the aggregation process of a long-acting lipidated therapeutic peptide: the case of semaglutide
The aggregation properties of semaglutide, a lipidated peptide drug agonist of the Glucagon-like peptide 1 receptor recently approved for the treatment of type 2 diabetes, have been investigated by spectroscopic techniques (UV-Vis absorption, steady-state and time-resolved fluorescence, and electronic circular dichroism) and molecular dynamics simulations. We show that in the micromolar concentration region, in aqueous solution, semaglutide is present as monomeric and dimeric species, with a characteristic monomer-to-dimer transition occurring at around 20 μM. The lipid chain stabilizes a globular morphology of the monomer and dimer species, giving rise to a locally well-defined polar outer surface where the lipid and peptide portions are packed to each other. At very long times, these peptide clusters nucleate the growth of larger aggregates characterized by blue luminescence and a β-sheet arrangement of the peptide chains. The understanding of the oligomerization and aggregation potential of peptide candidates is key for the development of long acting and stable drugs
On the background in the reaction and mixed event simulation
In this paper we evaluate sources of background for the , with the detected through its decay channel, to
compare with the experiment carried out at ELSA. We find background from
followed by decay of a into two ,
recombining one and one , and from the reaction with subsequent decay of the into two photons. This
background accounts for the data at invariant masses beyond 700
MeV, but strength is missing at lower invariant masses which was attributed to
photon misidentification events, which we simulate to get a good reproduction
of the experimental background. Once this is done, we perform an event mixing
simulation to reproduce the calculated background and we find that the method
provides a good description of the background at low invariant
masses but fakes the background at high invariant masses, making background
events at low invariant masses, which are due to misidentification
events, responsible for the background at high invariant masses which is due to
the and reactions.Comment: 10 pages, 5 figure
A Phenomenological Description of (\pi^{-}\Delta^{++}) Photo- and Electroproduction in Nucleon Resonance Region
The (\pi^{-}\Delta^{++}) production on the nucleon by real and virtual
photons is discussed as initial step in a simple model approach for the two
pion photo- and electroproduction on the nucleon, with emphasis on nucleon
resonance excitation which is of interest for new facilities like TJNAF. A
calculation for (\pi^{-}\Delta^{++}) channel in resonance excitation region is
presented and compared to existing experimental data along with a discussion of
physical effects that we find to be of relevance. The calculation is proposed
as a starting basis for the investigation of (N^{*}) electromagnetic form
factors using experimental data about two pion production by real and virtual
photons.Comment: 36 pages, 14 figures, to be published in Nucl. Phys.
Measurement of the Q(2) Dependence of the Deuteron Spin Structure Function g(1) and Its Moments at Low Q(2) with CLAS
We measured the g1 spin structure function of the deuteron at low Q2, where QCD can be approximated with chiral perturbation theory (χPT). The data cover the resonance region, up to an invariant mass of W ≈ 1.9  GeV. The generalized Gerasimov-Drell-Hearn sum, the moment Γd1 and the spin polarizability γ0d are precisely determined down to a minimum Q2 of 0.02  GeV2 for the first time, about 2.5 times lower than that of previous data. We compare them to several χPT calculations and models. These results are the first in a program of benchmark measurements of polarization observables in the χPT domain.
We measured the g1 spin structure function of the deuteron at low Q2, where QCD can be approximated with chiral perturbation theory (χPT). The data cover the resonance region, up to an invariant mass of W ≈1.9  GeV. The generalized Gerasimov-Drell-Hearn sum, the moment Γ_{1}^{d} and the spin polarizability γ_{0}^{d} are precisely determined down to a minimum Q2 of 0.02  GeV2 for the first time, about 2.5 times lower than that of previous data. We compare them to several χPT calculations and models. These results are the first in a program of benchmark measurements of polarization observables in the χPT domain
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