Fusion cross section measurements of astrophysical interest for light heavy ions systems within the STELLA project

This contribution is focused on the STELLA project (STELlar LAboratory), which aims at the measurement of fusion cross sections between light heavy ions like 12C+12C, 12C+16O or 16O+16O at deep subbarrier energies. The gamma-particle coincidence technique is used in order to reduce background contributions that become dominant for measurements in the nanobarn regime. The experimental setup composed of an ultra high vacuum reaction chamber, a set of 3 silicon strip detectors, up to 36 LaBr3(Ce) scintillators from the UK FATIMA collaboration, and a fast rotating target system will be described. The 12C+12C fusion reaction has been studied from Elab = 11 to 5.6 MeV using STELLA at the Andromède facility in Orsay, France. Preliminary commissioning results are presented in this article

The Cryptococcus neoformans transcriptome at the site of human meningitis.

Cryptococcus neoformans is the leading cause of fungal meningitis worldwide. Previous studies have characterized the cryptococcal transcriptome under various stress conditions, but a comprehensive profile of the C. neoformans transcriptome in the human host has not been attempted. Here, we extracted RNA from yeast cells taken directly from the cerebrospinal fluid (CSF) of two AIDS patients with cryptococcal meningitis prior to antifungal therapy. The patients were infected with strains of C. neoformans var. grubii of molecular type VNI and VNII. Using RNA-seq, we compared the transcriptional profiles of these strains under three environmental conditions (in vivo CSF, ex vivo CSF, and yeast extract-peptone-dextrose [YPD]). Although we identified a number of differentially expressed genes, single nucleotide variants, and novel genes that were unique to each strain, the overall expression patterns of the two strains were similar under the same environmental conditions. Specifically, yeast cells obtained directly from each patient's CSF were more metabolically active than cells that were incubated ex vivo in CSF. Compared with growth in YPD, some genes were identified as significantly upregulated in both in vivo and ex vivo CSF, and they were associated with genes previously recognized for contributing to pathogenicity. For example, genes with known stress response functions, such as RIM101, ENA1, and CFO1, were regulated similarly in the two clinical strains. Conversely, many genes that were differentially regulated between the two strains appeared to be transporters. These findings establish a platform for further studies of how this yeast survives and produces disease

Cyto-mechanoresponsive polyelectrolyte multilayer films.

Cell adhesion processes take place through mechanotransduction mechanisms where stretching of proteins results in biological responses. In this work, we present the first cyto-mechanoresponsive surface that mimics such behavior by becoming cell-adhesive through exhibition of arginine-glycine-aspartic acid (RGD) adhesion peptides under stretching. This mechanoresponsive surface is based on polyelectrolyte multilayer films built on a silicone sheet and where RGD-grafted polyelectrolytes are embedded under antifouling phosphorylcholine-grafted polyelectrolytes. The stretching of this film induces an increase in fibroblast cell viability and adhesion.journal articleresearch support, non-u.s. gov't2012 Jan 112011 12 20importe

0357 : Platypnea orthodeoxia syndrome: focus on predisposing anatomical factors

Platypnea orthodeoxia syndrome (POS) is a rare situation with hypoxia and breathlessness in the upright position recovering in the recumbent position. A mechanical inter-atrial septum distortion, causing redirection of flow from the right to the left atrium through a patent foramen ovale (PFO), despite normal pulmonary pressure, is suggested to explain POS. Prevalence of predisposing anatomical factors remain little knownMethodsAll patients who underwent a PFO closure for a POS were retrospectively included from 2 CHU. Predisposing anatomical factors were investigated.Results67 patients (Median age 72 y.o., interquartile range 61-80; 58.2% men) were included. All patients had dyspnea (76.2% NYHA III or IV, 53.7% under oxygen-therapy). The remaining patients had a refractory hypoxemia (38.2%) without POS. Most frequent predisposing anatomical factor was an enlarged or unwound aorta (n=29, 43.3% 95CI 31.2-56.0) with an aortic aneurysm in 25 patients (37.3%, 95CI 25.8-50.0). Other factors identified were pneumonectomy (n=8, 11.9% CI95 5.3-22.2), a history of cardiac surgery (n=7, 10.5%, 95CI 4.3-20.3), mechanical ventilation (n=6, 9.0% 95CI 3.4-18.5), kyphoscoliosis (n=4, 6.0% 95CI 1.7-14.6), hepatomegaly (n=4, 6.0% 95CI 1.7-14.6, 2 patients with hepato-renal polycystic disease, one hemochromatosis and one cirrhosis), right ventricle failure (n=2,3.0% 95CI 0.4-10.4), pericardial effusions (n=2,3.0% 95CI 0.4-10.4), right ventricle arrhythmogenic dysplasia (n=2,3.0% 95CI 0.4-10.4), diaphragmatic paralysis (n=1, 1.5% 95CI 0.1-8.0), carcinoid syndrome with tricuspid regurgitation (n=1, 1.5% 95CI 0.1-8.0), a right atrium pace-maker lead (n=1, 1.5% 95CI 0.1-8.0) and a tako-tsubo syndrome (n=1, 1.5% 95CI 0.1-8.0).ConclusionAortic aneurysm and pneumonectomy are the most frequent situation leading to a POS. Other causes were observed such as hepato-renal polycystic kidney, or atrial pacemaker probe that may be underdiagnosed in clinical practice

Fluorescent and magnetic stellate mesoporous silica for bimodal imaging and magnetic hyperthermia

There is currently a crucial need of innovative multifunctional nanoparticles combining, in one formulation, imaging and therapy capacities allowing thus an accurate diagnosis and a therapy monitored by imaging. Multimodal imaging will ensure to speed up diagnosis, and to increase its sensitivity, reliability and specificity for a better management of the disease. Combined with a therapeutic action, it will also enable to treat the disease in a specific personalized manner in feedback mode. The mastered design of such bioprobes as well as the demonstration of their efficiency are still challenges to face in nanomedicine. In this work, novel fluorescent and magnetic core–shell nanocomposites have been designed to ensure, in one nanoformulation, bimodal fluorescence and MRI imaging coupled with therapy by magnetic hyperthermia. They consist in the coating of a magnetic iron oxide (IO) core (ca. 18 nm diameter to ensure magnetic hyperthermia) by an original large pore stellate mesoporous silica (STMS) shell to produce uniform and mono-core magnetic core–shell nanocomposites denoted IO@STMS NPs. To confer fluorescence properties, CdSe/ZnS quantum dots (QDs) NPs were grafted inside the large pores of the IO@STMS nanocomposites. To provide biocompatibility and opsonization-resistance, a tightly-bound human serum albumin (HSA) coating is added around the nanocomposite using an original IBAM-based strategy. Cellular toxicity and non-specific cell–nanomaterial interactions allowed to determine a concentration range for safe application of these NPs. Cellular endosomes containing spontaneously-uptaken NPs displayed strong and photostable QD fluorescence signals while magnetic relaxivity measurements confirm their suitability as contrast agent for MRI. HeLa cell-uptaken NPs exposed to a magnetic field of 100 kHz and 357 Gauss (or 28.5 kA m−1) display an outstanding 65% cell death at a very low iron concentration (1.25 μg Fe mL−1), challenging current magnetic hyperthermia nanosystems. Furthermore, at the particularly demanding conditions of clinical use with low frequency and amplitude field (100 kHz, 117 Gauss or 9.3 kA m−1), magnetic hyperthermia combined with the delivery of a chemotherapeutic drug, doxorubicin, allowed 46% cell death, which neither the drug nor the NPs alone yielded, evidencing thus the synergistic effect of this combined treatment.Facultad de Ciencias VeterinariasInstituto de Investigaciones Fisicoquímicas Teóricas y AplicadasInstituto de Física La Plat

Performance of Pyridylthiourea-Polyethylenimine Polyplex for siRNA-Mediated Liver Cancer Therapy in Cell Monolayer, Spheroid, and Tumor Xenograft Models

Medical application of siRNAs relies on methods for delivering nucleic acids into the cytosol. Synthetic carriers, which assemble with nucleic acids into delivery systems, show promises for cancer therapy but efficiency remains to be improved. In here, the effectiveness of pyridylthiourea‐polyethylenimine (πPEI), a siRNA carrier that favors both polyplex disassembly and endosome rupture upon sensing the acidic endosomal environment, in 3 experimental models of hepatocellular cancer is tested. The πPEI‐assisted delivery of a siRNA targeting the polo‐like kinase 1 into Huh‐7 monolayer produces a 90% cell death via a demonstrated RNA interference mechanism. Incubation of polyplex with Huh‐7 spheroids leads to siRNA delivery into the superficial first cell layer and a 60% reduction in spheroid growth compared to untreated controls. Administration of polyplexes into mice bearing subcutaneous implanted Huh‐7Luc tumors results in a reduced tumor progression, similar to the one observed in the spheroid model. Altogether, these results support the in vivo use of synthetic and dedicated polymers for increasing siRNA‐mediated gene knockdown, and their clinical promise in cancer therapeutics

Constraints on the χ_(c1) versus χ_(c2) polarizations in proton-proton collisions at √s = 8 TeV

The polarizations of promptly produced χ_(c1) and χ_(c2) mesons are studied using data collected by the CMS experiment at the LHC, in proton-proton collisions at √s=8  TeV. The χ_c states are reconstructed via their radiative decays χ_c → J/ψγ, with the photons being measured through conversions to e⁺e⁻, which allows the two states to be well resolved. The polarizations are measured in the helicity frame, through the analysis of the χ_(c2) to χ_(c1) yield ratio as a function of the polar or azimuthal angle of the positive muon emitted in the J/ψ → μ⁺μ⁻ decay, in three bins of J/ψ transverse momentum. While no differences are seen between the two states in terms of azimuthal decay angle distributions, they are observed to have significantly different polar anisotropies. The measurement favors a scenario where at least one of the two states is strongly polarized along the helicity quantization axis, in agreement with nonrelativistic quantum chromodynamics predictions. This is the first measurement of significantly polarized quarkonia produced at high transverse momentum