2,384 research outputs found
First results from the new PVLAS apparatus: a new limit on vacuum magnetic birefringence
Several groups are carrying out experiments to observe and measure vacuum
magnetic birefringence, predicted by Quantum Electrodynamics (QED). We have
started running the new PVLAS apparatus installed in Ferrara, Italy, and have
measured a noise floor value for the unitary field magnetic birefringence of
vacuum T (the error
represents a 1 deviation). This measurement is compatible with zero and
hence represents a new limit on vacuum magnetic birefringence deriving from non
linear electrodynamics. This result reduces to a factor 50 the gap to be
overcome to measure for the first time the value of predicted by QED:
~T. These birefringence measurements also yield improved
model-independent bounds on the coupling constant of axion-like particles to
two photons, for masses greater than 1 meV, along with a factor two improvement
of the fractional charge limit on millicharged particles (fermions and
scalars), including neutrinos
New PVLAS model independent limit for the axion coupling to for axion masses above 1meV
During 2014 the PVLAS experiment has started data taking with a new apparatus
installed at the INFN Section of Ferrara, Italy. The main target of the
experiment is the observation of magnetic birefringence of vacuum. According to
QED, the ellipticity generated by the magnetic birefringence of vacuum in the
experimental apparatus is expected to be . No ellipticity signal is present so far with a noise floor
after 210 hours of data taking.
The resulting ellipticity limit provides the best model independent upper limit
on the coupling of axions to for axion masses above eV
Measurement of the Cotton Mouton effect of water vapour
In this paper we report on a measurement of the Cotton Mouton effect of water
vapour. Measurement performed at room temperature ( K) with a wavelength
of 1064 nm gave the value for the
unit magnetic birefringence (1 T magnetic field and atmospheric pressure)
(2-Aminobenzothiazole)-Methyl-1,1-bisphosphonic acids: Targeting matrix metalloproteinase 13 inhibition to the bone
Matrix Metalloproteinases (MMPs) are a family of secreted and membrane-bound enzymes, of which 24 isoforms are known in humans. These enzymes degrade the proteins of the extracellular matrix and play a role of utmost importance in the physiological remodeling of all tissues. However, certain MMPs, such as MMP-2, -9, and -13, can be overexpressed in pathological states, including cancer and metastasis. Consequently, the development of MMP inhibitors (MMPIs) has been explored for a long time as a strategy to prevent and hinder metastatic growth, but the important side effects linked to promiscuous inhibition of MMPs prevented the clinical use of MMPIs. Therefore, several strategies were proposed to improve the therapeutic profile of this pharmaceutical class, including improved selectivity toward specific MMP isoforms and targeting of specific organs and tissues. Combining both approaches, we conducted the synthesis and preliminary biological evaluation of a series of (2-aminobenzothiazole)-methyl-1,1-bisphosphonic acids active as selective inhibitors of MMP-13 via in vitro and in silico studies, which could prove useful for the treatment of bone metastases thanks to the bone-targeting capabilities granted by the bisphosphonic acid group
Bridging the future of cardiac stimulation: physiologic or leadless pacing?
Cardiac simulation has moved from early life-saving pacemakers meant only to prevent asystole to current devices capable of physiologic stimulation for the treatment of heart rhythm and heart failure, that are also intended for remote patient and disease-progression monitoring. The actual vision of contemporary pacing aims to correct the electrophysiologic roots of mechanical inefficiency regardless of underlying structural heart diseases. The awareness of the residual cardiac dyssynchrony related to customary cardiac pacing has changed the concept of what truly represents “physiologic pacing”. On a different perspective, leadless stimulation to abolish CIED surgery and prevent lead-related complications is becoming a priority both for young device recipients and for frail, elderly patients. Careful clinical evaluation attempts to bridge decision-making to patient-tailored therapy
Novel Rivastigmine Derivatives as Promising Multi-Target Compounds for Potential Treatment of Alzheimer’s Disease
Alzheimer’s disease (AD) is the most serious and prevalent neurodegenerative disorder still without cure. Since its aetiology is diverse, recent research on anti-AD drugs has been focused on multi-target compounds. In this work, seven novel hybrids (RIV–BIM) conjugating the active moiety of the drug rivastigmine (RIV) with 2 isomeric hydroxyphenylbenzimidazole (BIM) units were developed and studied. While RIV assures the inhibition of cholinesterases, BIM provides further appropriate properties, such as inhibition of amyloid β-peptide (Aβ) aggregation, antioxidation and metal chelation. The evaluated biological properties of these hybrids included antioxidant activity; inhibition of acetylcholinesterase (AChE), butyrylcholinesterase (BChE) and Aβ42 aggregation; as well as promotion of cell viability and neuroprotection. All the compounds are better inhibitors of AChE than rivastigmine (IC50 = 32.1 µM), but compounds of series 5 are better inhibitors of BChE (IC50 = 0.9−1.7 µM) than those of series 4. Series 5 also showed good capacity to inhibit self- (42.1−58.7%) and Cu(II)-induced (40.3−60.8%) Aβ aggregation and also to narrow (22.4−42.6%) amyloid fibrils, the relevant compounds being 5b and 5d. Some of these compounds can also prevent the toxicity induced in SH-SY5Y cells by Aβ42 and oxidative stress. Therefore, RIV–BIM hybrids seem to be potential drug candidates for AD with multi-target abilities.Depto. de Química AnalíticaFac. de Ciencias QuímicasTRUEPortuguese Fundação para a Ciência e Tecnologia (FCT)Ministerio de Ciencia e InnovaciónComunidad de Madrid and European funding from FSE and FEDER programsMinisterio de Ciencia, Innovación y UniversidadesErasmus+ programpu
Growth and Fat Mass in Preterm Infants Fed A Protein-Enriched Postdischarge Formula (PDF): A Randomized Controlled Trial
Background and aims: Male infants with BW< 1250 g benefit from PDF. Fetal growth seems to influence growth recovery whereas fat restoration occurs irrespective of BW. To evaluate whether being fed a PDF determines a growth benefit in two subgroups of infants.
Methods: 123 preterm infants born AGA (BW=1193.4\ub1 230 g; GA=29\ub11.9 wks) and 84 born SGA (BW=1127\ub1 262g; GA=31.3\ub11.9 wks) were randomized at term corrected age (CA) in G1: 59 AGA fed PDF (2.9 g/100 kcal), G2: 64 AGA fed term formula (TF) (2.1 g/100 kcal), G3: 41 SGA fed PDF, G4: 43 SGA fed TF. From 6 months infants were fed a follow on formula and weaned according to ESPGHAN recommendations. Growth and body composition were assessed by an air displacement plethysmography system at term, 1, 3, 5, 6, 12 months. ANOVA, regression analysis.
Results: G1 and G3 protein intakes were higher than those of G2 (p< 0.005) and G4(p< 0.05), respectively, whereas weight, length and fat mass were similar at each study point. G1 mean HC (cm) was bigger than that of G2 at six months (43.5\ub1 1.9 vs 42.6\ub11.6, p=0.03) whereas at 12 months no difference was found (45.4\ub11.6 vs 46\ub11.6). In AGA infants being fed a PDF formula, being male, not having a postnatal growth retardation at term correlated with bigger HC at six months [(p< 0.001), unstandardized B coefficient (SE) 0.9 (0.36); 1.2 (0.36); 1.2 (0.37), respectively].
Conclusions: Male AGA without postnatal growth retardation at term but not SGA infants appear to benefit from being fed PDF
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