Detection of Pseudomonas aeruginosa in sputum samples by modified fluorescent in situ hybridization

Pseudomonas aeruginosa is the most common and dominant infectious agent that causes chronic pneumonia in patients with cystic fibrosis (CF). Fluorescent in situ hybridization (FISH) is a powerfulmolecular method for the specific and rapid diagnosis of bacteria, including the detection of P. aeruginosa in sputum samples from CF patients. High background fluorescence of viscous sputumsamples obtained from CF patients may impede detection of microorganisms by FISH. The aim of this study was to test the application of biotin during FISH technique to reduce unspecific background fluorescence in sputum samples to facilitate and improve detection of P. aeruginosa. Sixty-three sputum samples from CF patients were tested by FISH to detect P. aeruginosa. All the 63 samples were also examined by a modified FISH procedure including biotin treatment. The FISH results were compared with those of conventional culture method. The specificity of FISH was 100%. The sensitivity of FISH for detection of P. aeruginosa from samples without biotin treatment was 83.3%, whereas in biotin-treated samples was 88.1%. Biotin reduced background fluorescence of 12 sputum samples of CF patients and it did not show any adverse effect on FISH results of the remaining sputum samples. Therefore, using of biotin in FISH procedure seems to facilitate and improve the detection of respiratorytract infections by P. aeruginosa in this population

Extracting the depolarization coefficient D_NN from data measured with a full acceptance detector

The spin transfer from vertically polarized beam protons to Lambda or Sigma hyperons of the associated strangeness production pp -> pK Lambda (Sigma) is described with the depolarization coefficient D_NN. As the polarization of the hyperons is determined by their weak decays, detectors, which have a large acceptance for the decay particles, are needed. In this paper a formula is derived, which describes the depolarization coefficient D_NN by count rates of a 4 pi detector. It is shown, that formulas, which are given in publications for detectors with restricted acceptance, are specific cases of this formula for a 4 pi detector.Comment: Accepted for publication by Nuclear Instruments and Methods in Physics Research Section

Novel Polymorph of GaSe

2D GaSe is a semiconductor belonging to the group of post-transition metal chalcogenides with great potential for advanced optoelectronic applications. The weak interlayer interaction in multilayer 2D materials allows the formation of several polymorphs. Here, the first structural observation of a new GaSe polymorph is reported, characterized by a distinct atomic configuration with a centrosymmetric monolayer (D-3d point group). The atomic structure of this new GaSe polymorph is determined by aberration-corrected scanning transmission electron microscopy. Density-functional theory calculations verify the structural stability of this polymorph. Furthermore, the band structure and Raman intensities are calculated, predicting slight differences to the currently known polymorphs. In addition, the occurrence of layer rotations, interlayer relative orientations, as well as translation shear faults is discussed. The experimental confirmation of the new GaSe polymorph indicates the importance of investigating changes in the crystal structure, which can further impact the properties of this family of compoundsThis article has received support from the project Nanotechnology Based Functional Solutions (NORTE-01-0145-FEDER-000019), supported by Norte Portugal Regional Operational Programme (NORTE2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (ERDF). Additional support by National Funds through the Portuguese Foundation for Science and Technology (FCT) in the framework of the project "LA2D" -PTDC/FIS-NAN/3668/2014 is acknowledged. This work was supported by FCT, through IDMEC, under LAETA, project UIDB/50022/2020. A. M.-S. thanks the Marie-Curie-COFUND program Nano TRAIN for Growth II (Grant Agreement 713640) and the Ramon y Cajal programme (grant RYC2018-024024-I, MINECO, Spain). This work was carried out in part through the use of the INL Advanced Electron Microscopy, Imaging, and Spectroscopy Facility. The computations were performed on the Tirant III cluster of the Servei d'Informatica of the University of Valencia (project vlc82) and on Mare Nostrum cluster of the Barcelona Supercomputing Center (project FI-2020-2-033 and FI-2020-3-0021)

Determination of the eta'-proton scattering length in free space

Taking advantage of both the high mass resolution of the COSY-11 detector and the high energy resolution of the low-emittance proton-beam of the Cooler Synchrotron COSY we determine the excitation function for the pp --> pp eta' reaction close-to-threshold. Combining these data with previous results we extract the scattering length for the eta'-proton potential in free space to be Re(a_{p eta'}) = 0+-0.43 fm and Im(a_{p eta'}) = 0.37(+0.40)(-0.16) fm.Comment: 5 pages, 3 figures, accepted for publication in Phys. Rev. Let

One-Particle Measurement of the Antiproton Magnetic Moment

\DeclareRobustCommand{\pbar}{\HepAntiParticle{p}{}{}\xspace} \DeclareRobustCommand{\p}{\HepParticle{p}{}{}\xspace} \DeclareRobustCommand{\mup}{$\mu_{p}${}{}\xspace} \DeclareRobustCommand{\mupbar}{\mu_{\pbar}{}{}\xspace} \DeclareRobustCommand{\muN}{$\mu_N${}{}\xspace For the first time a single trapped \pbar is used to measure the \pbar magnetic moment {\bm\mu}_{\pbar}. The moment {\bm\mu}_{\pbar} = \mu_{\pbar} {\bm S}/(\hbar/2) is given in terms of its spin ${\bm S}$ and the nuclear magneton (\muN) by \mu_{\pbar}/\mu_N = -2.792\,845 \pm 0.000\,012. The 4.4 parts per million (ppm) uncertainty is 680 times smaller than previously realized. Comparing to the proton moment measured using the same method and trap electrodes gives \mu_{\pbar}/\mu_p = -1.000\,000 \pm 0.000\,005 to 5 ppm, for a proton moment ${\bm{\mu}}_{p} = \mu_{p} {\bm S}/(\hbar/2)$, consistent with the prediction of the CPT theorem.Comment: 4 pages, 4 figures. arXiv admin note: substantial text overlap with arXiv:1201.303

Microstructure and defect analysis in the vicinity of blisters in polycrystalline tungsten

AbstractUp to now, analyzing the production of dislocation-type defects in the subsurface region of plasma or ion-exposed tungsten samples has been hampered by the challenging production of suitable cross-section samples for transmission electron microscopy. We present two reliable methods based on precision electropolishing to prepare cross-sections of tungsten that allow direct imaging of dislocation-type defects by scanning as well as by transmission electron microscopy. Using these methods, we are able to demonstrate a clear enhancement of the dislocation density in the caps of blisters on tungsten exposed to H isotope plasma, i.e., of surface morphologies that are correlated to subsurface cavities. As a benchmark, we also show a cross-section of tungsten irradiated by 20 MeV W6+ ions

Hadronic interaction of eta and eta-prime mesons with nucleons

Due to their short life-time, flavour-neutral mesons cannot be utilized as free secondary beams or targets, and therefore a study of their interaction with nucleons is not possible via direct scattering experiments. This interaction is, however, accessible via its influence on the energy dependence - and on the phase space distributions of the cross sections for reactions in which these mesons are produced. In case of the p p --> p p eta reaction the experimentally determined distributions of the differential cross sections close to the production threshold cannot be described by taking into account the S-wave proton-proton and proton-eta interaction only. Here we show that the angular distributions determined at the COSY-11 facility reveal some evidence for P-wave admixture in the proton-proton subsystem already at an excess energy as low as Q = 15.5 MeV. We also present that one can estimate the relative strength of the eta-nucleon and eta-prime-nucleon interactions by comparison of the eta and eta-prime production yield.Comment: 4 pages, 3 figures, Talk given at 16th International Conference on Particles and Nuclei (PANIC 02), Osaka, Japan, 30 Sep - 4 Oct 200

Experimental study of the eta-meson interaction with two-nucleons

By means of the COSY-11 detection system, using a stochastically cooled proton beam of the cooler synchrotron COSY and a hydrogen cluster target, we have performed a high statistics measurement of the pp --> pp eta reaction at an excess energy of Q = 15.5 MeV. The experiment was based on the four-momentum determination of both outgoing protons. This permits to identify pp --> pp eta events and to derive the complete kinematical information of the eta-p-p-system allowing for subsequent investigations of the eta-p interaction. The observed spectrum of the invariant mass of the proton-proton system deviates strongly from the phase-space distribution revealing the influence of the final-state-interaction among the outgoing particles or nontrivial features of the primary production mechanism.Comment: 6 pages, 4 figures, Talk presented at Meson 2002, 7th International Workshop on Meson Production, Properties and Interaction, Cracow, Poland, 24-28 May 200

Heavy Meson Production at COSY - 11

The COSY-11 collaboration has measured the total cross section for the pp --> pp eta-prime and pp --> pp eta reactions in the excess energy range from Q = 1.5 MeV to Q = 23.6 MeV and from Q = 0.5 MeV to Q = 5.4 MeV, respectively. Measurements have been performed with the total luminosity of 73 nb^(-1) for the pp --> pp eta reaction and 1360 nb^(-1) for the pp --> pp eta-prime one. Recent results are presented and discussed.Comment: Invited talk at 4th International Conference on Physics at Storage Rings (STORI 99), Bloomington, Indiana, USA, September 12-16, 199