1,179 research outputs found
A simple thermodynamical witness showing universality of macroscopic entanglement
We show that if the ground state entanglement exceeds the total entropy of a
given system, then this system is in an entangled state. This is a universal
entanglement witness that applies to any physical system and yields a
temperature below which we are certain to find some entanglement. Our witness
is then applied to generic bosonic and fermionic many body systems to derive
the corresponding "critical" temperatures that have a very broad validity.Comment: 3 pages, Torun conference, June 25-28, 200
Effects of human pharmaceuticals on cytotoxicity, EROD activity and ROS production in fish hepatocytes.
Pharmaceuticals are found in the aquatic environment but their potential effects on non-target species like fish remain unknown. This in vitro study is a first approach in the toxicity assessment of human drugs on fish. Nine pharmaceuticals were tested on two fish hepatocyte models: primary cultures of rainbow trout hepatocytes (PRTH) and PLHC-1 fish cell line. Cell viability, interaction with cytochrome P450 1A (CYP1A) enzyme and oxidative stress were assessed by using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrasodium bromide tetrazolium (MTT), 7-ethoxyresorufin-o-deethylase (EROD) and dichlorofluorescein (DCFH-DA) assays, respectively. The tested drugs were clofibrate (CF), fenofibrate (FF), carbamazepine (CBZ), fluoxetine (FX), diclofenac (DiCF), propranolol (POH), sulfamethoxazole (SFX), amoxicillin (AMX) and gadolinium chloride (GdCl(3)). All substances were cytotoxic, except AMX at concentration up to 500 microM. The calculated MTT EC(50) values ranged from 2 microM (CF) to 651 microM (CBZ) in PLHC-1, and from 53 microM (FF) to 962 microM (GdCl(3)) in PRTH. CF, FF, and FX were the most cytotoxic drugs and induced oxidative stress before being cytotoxic. Compared to hepatocytes from human and dog, fish hepatocytes seemed to be more susceptible to the peroxisome proliferators (PPs) CF and FF. In PLHC-1 cells none of the tested drugs induced the EROD activity whereas POH appeared as a weak EROD inducer in PRTH. Moreover, in PRTH, SFX, DiCF, CBZ and to a lesser extend, FF and CF inhibited the basal EROD activity at clearly sublethal concentrations which may be of concern at the biological and chemical levels in a multipollution context
Probing pre-formed alpha particles in the ground state of nuclei
In this Letter, we report on alpha particle emission through the nuclear
break-up in the reaction 40Ca on a 40Ca target at 50A MeV. It is observed that,
similarly to nucleons, alpha particles can be emitted to the continuum with
very specific angular distribution during the reaction. The alpha particle
properties can be understood as resulting from an alpha cluster in the daughter
nucleus that is perturbed by the short range nuclear attraction of the
collision partner and emitted. A time-dependent theory that describe the alpha
particle wave-function evolution is able to reproduce qualitatively the
observed angular distribution. This mechanism offers new possibilities to study
alpha particle properties in the nuclear medium.Comment: 4 pages, 3 figure
Soft laser-plasma X-ray source for differential absorption imaging of tracing elements in thin samples
The differential imaging technique is particularly suitable for the
detection of small concentrations of contrasts agents for biological
and medical applications in samples using X-ray radiography. In this
paper, we present an application of this technique using a laser-plasma
soft X-ray source combined with a bent crystal. Using a Fresnel plate
as a test object, we were able to obtain spatial resolutions of the
order of a few tens of microns. The use of our configuration to perform
differential imaging of a test-sample at the L2 edge of Br
at 1,596 eV is finally demonstrated
The PLASMONX Project for advanced beam physics experiments
The Project PLASMONX is well progressing into its
design phase and has entered as well its second phase of
procurements for main components. The project foresees
the installation at LNF of a Ti:Sa laser system (peak
power > 170 TW), synchronized to the high brightness
electron beam produced by the SPARC photo-injector.
The advancement of the procurement of such a laser
system is reported, as well as the construction plans of a
new building at LNF to host a dedicated laboratory for
high intensity photon beam experiments (High Intensity
Laser Laboratory). Several experiments are foreseen
using this complex facility, mainly in the high gradient
plasma acceleration field and in the field of mono-
chromatic ultra-fast X-ray pulse generation via Thomson
back-scattering. Detailed numerical simulations have
been carried out to study the generation of tightly focused
electron bunches to collide with laser pulses in the
Thomson source: results on the emitted spectra of X-rays
are presented
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