Excited States in 52Fe and the Origin of the Yrast Trap at I=12+

Excited states in 52Fe have been determined up to spin 10\hbar in the reaction 28Si + 28Si at 115 MeV by using \gamma-ray spectroscopy methods at the GASP array. The excitation energy of the yrast 10+ state has been determined to be 7.381 MeV, almost 0.5 MeV above the well known \beta+-decaying yrast 12+ state, definitely confirming the nature of its isomeric character. The mean lifetimes of the states have been measured by using the Doppler Shift Attenuation method. The experimental data are compared with spherical shell model calculations in the full pf-shell.Comment: 9 pages, RevTeX, 7 figures include

Relationship between pp65 antigenemia levels and real-time quantitative DNA PCR for Human Cytomegalovirus (HCMV) management in immunocompromised patients

<p>Abstract</p> <p>Background</p> <p>Quantitative real-time PCR assays, which are more rapid and practical than pp65 antigenemia determination, are progressively becoming the preferred method for monitoring Human Cytomegalovirus (HCMV) reactivation. However, the relationship between HCMV DNA and antigenemia levels is still under investigation. The aim of this study was to analyse the relationship between HCMV DNA and pp65 antigenemia levels in order to identify clinically useful threshold values for the management of patients.</p> <p>Methods</p> <p>475 consecutive samples from 156 immunosuppressed patients were tested for HCMV by pp65 antigenemia and Real-time PCR assay.</p> <p>Results </p> <p>136 out of 475 consecutive samples derived from 48 patients showed evidence of HCMV infection. HCMV DNA was detected in 106 samples, pp65 antigen in 3, and both markers in 27. pp65 antigen detection was associated with higher HCMV DNA levels. The cut-off HCMV DNA level that best predicted pp65 antigenemia in this series of samples was 11,500 copies/ml, but different threshold levels could be observed for specific groups of patients. HCMV disease was observed in 5 out of 48 patients with active HCMV infection. The presence of clinical symptoms was associated with positive pp65 and with higher antigenemia levels. Higher HCMV DNA load at the onset of viral replication was correlated to the development of clinical symptoms.</p> <p>Conclusion</p> <p>Both pp65 antigenemia and HCMV DNA load can be useful for the prospective monitoring of immunocompromised subjects. Specific cut-off levels capable of triggering preemptive antiviral treatment should be determined in accordance to the type of test used and the characteristics of patients and prospectively validated.</p

Coexistence of 'alpha+ 208Pb' cluster structures and single-particle excitations in 212Po

Excited states in 212Po have been populated by alpha transfer using the 208Pb(18O,14C) reaction at 85MeV beam energy and studied with the EUROBALL IV gamma multidetector array. The level scheme has been extended up to ~ 3.2 MeV excitation energy from the triple gamma coincidence data. Spin and parity values of most of the observed states have been assigned from the gamma angular distributions and gamma -gamma angular correlations. Several gamma lines with E(gamma) < 1 MeV have been found to be shifted by the Doppler effect, allowing for the measurements of the associated lifetimes by the DSAM method. The values, found in the range [0.1-0.6] ps, lead to very enhanced E1 transitions. All the emitting states, which have non-natural parity values, are discussed in terms of alpha-208Pb structure. They are in the same excitation-energy range as the states issued from shell-model configurations.Comment: 21 pages, 19 figures, corrected typos, revised arguments in Sect. III

Comparative Evaluation of Three Automated Systems for DNA Extraction in Conjunction with Three Commercially Available Real-Time PCR Assays for Quantitation of Plasma Cytomegalovirus DNAemia in Allogeneic Stem Cell Transplant Recipients▿

Limited data are available on the performance of different automated extraction platforms and commercially available quantitative real-time PCR (QRT-PCR) methods for the quantitation of cytomegalovirus (CMV) DNA in plasma. We compared the performance characteristics of the Abbott mSample preparation system DNA kit on the m24 SP instrument (Abbott), the High Pure viral nucleic acid kit on the COBAS AmpliPrep system (Roche), and the EZ1 Virus 2.0 kit on the BioRobot EZ1 extraction platform (Qiagen) coupled with the Abbott CMV PCR kit, the LightCycler CMV Quant kit (Roche), and the Q-CMV complete kit (Nanogen), for both plasma specimens from allogeneic stem cell transplant (Allo-SCT) recipients (n = 42) and the OptiQuant CMV DNA panel (AcroMetrix). The EZ1 system displayed the highest extraction efficiency over a wide range of CMV plasma DNA loads, followed by the m24 and the AmpliPrep methods. The Nanogen PCR assay yielded higher mean CMV plasma DNA values than the Abbott and the Roche PCR assays, regardless of the platform used for DNA extraction. Overall, the effects of the extraction method and the QRT-PCR used on CMV plasma DNA load measurements were less pronounced for specimens with high CMV DNA content (>10,000 copies/ml). The performance characteristics of the extraction methods and QRT-PCR assays evaluated herein for clinical samples were extensible at cell-based standards from AcroMetrix. In conclusion, different automated systems are not equally efficient for CMV DNA extraction from plasma specimens, and the plasma CMV DNA loads measured by commercially available QRT-PCRs can differ significantly. The above findings should be taken into consideration for the establishment of cutoff values for the initiation or cessation of preemptive antiviral therapies and for the interpretation of data from clinical studies in the Allo-SCT setting

Extracellular enzyme production in the coastal upwelling system off Peru during different upwelling scenarios: a mesocosm experiment

The Peruvian upwelling system is a highly productive ecosystem that could be altered by ongoing global changes. We carried out a mesocosm experiment off Peru, with the addition of water masses from the regional oxygen minimum zone (OMZ) collected at two different sites simulating two different upwelling scenarios. Here we focus on pelagic remineralization of organic matter by extracellular enzyme production of leucine aminopeptidase (LAP) and alkaline phosphatase activity (APA). After addition of the OMZ water, dissolved inorganic nitrogen (N) was depleted, but the standing stock of phytoplankton was relatively high even after nutrient depletion (mostly &gt;4 &micro;g chlorophyll a L-1). During the initial phase of the experiment, APA was 0.6 nmol L-1 h-1 even though the PO43- concentration was &gt;0.5 &micro;mol L-1. Initially, the dissolved organic phosphorus (DOP) decreased, coinciding with an increase in PO43- concentration probably linked to the APA. The LAP activity was very high with most of the measurements in the range 200&ndash;800 nmol L-1 h-1. This enzyme degrades amino acids and these high values are probably linked to the highly productive, but N-limited coastal ecosystem. Also, the experiment took place during a rare coastal El Ni&ntilde;o event with higher-than-normal surface temperatures, which could have affected the enzyme production. Using a non-parametric multidimensional scaling analysis (NMDS) with a generalized additive model (GAM), we found that biogeochemical variables (e.g. nutrient and chlorophyll a concentrations), phytoplankton and bacterial communities explained up to 64 % of the variability in APA. The bacterial community explained best the variability (34 %) in LAP. The high hydrolysis rates for this enzyme suggests that pelagic N remineralization supported the high standing stock of primary producers in the mesocosms after N depletion.</p

E0 Transitions and the Depopulation of SD Bands

We present the results of calculations showing that E0 transitions may successfully compete with other types of electromagnetic transitions in the decay out of SD bands