Measurements of fusion reactions of low-intensity radioactive carbon beams on 12C and their implications for the understanding of X-ray bursts.

The interaction between neutron-rich nuclei plays an important role for understanding the reaction mechanism of the fusion process as well as for the energy production through pycnonuclear reactions in the crust of neutron stars. We have performed the first measurements of the total fusion cross sections in the systems (10,14,15)C+(12)C using a new active target-detector system. In the energy region accessible with existing radioactive beams, a good agreement between the experimental and theoretical cross sections is observed. This gives confidence in our ability to calculate fusion cross sections for systems which are outside the range of today's radioactive beam facilities.

Fusion reactions with the one-neutron halo nucleus (15)C.

The structure of (15)C, with an s(1/2) neutron weakly bound to a closed-neutron shell nucleus (14)C, makes it a prime candidate for a one-neutron halo nucleus. We have for the first time studied the cross section for the fusion-fission reaction (15)C+(232)Th at energies in the vicinity of the Coulomb barrier and compared it to the yield of the neighboring (14)C+(232)Th system measured in the same experiment. At sub-barrier energies, an enhancement of the fusion yield by factors of 2-5 was observed for (15)C, while the cross sections for (14)C match the trends measured for (12,13)C.

First experiment with HELIOS: the structure of 13B.

A first experiment is reported that makes use of a new kind of spectrometer uniquely suited to the study of reactions with radioactive beams in inverse kinematics, the helical orbit spectrometer, HELIOS. The properties of some low-lying states in the neutron-rich N=8 nucleus 13B were studied with good resolution. From the measured angular distributions of the (d,p) reaction and the relative spectroscopic factors, spin and configuration assignments of the first- and third-excited states of this nucleus can be constrained.

Epithelial-neutrophil activating peptide (ENA-78) is an important angiogenic factor in non-small cell lung cancer.

We report here the role of the CXC chemokine, epithelial neutrophil activating peptide (ENA-78), as an angiogenic factor in human non-small cell lung cancer (NSCLC). In freshly isolated human specimens of NSCLC, elevated levels of ENA-78 were found that strongly correlated with the vascularity of the tumors. In a SCID mouse model of human NSCLC tumorigenesis, expression of ENA-78 in developing tumors correlated with tumor growth in two different NSCLC cell lines. Furthermore, passive immunization of NSCLC tumor-bearing mice with neutralizing anti-ENA-78 antibodies reduced tumor growth, tumor vascularity, and spontaneous metastases, while having no effect on the proliferation of NSCLC cells either in vitro or in vivo. These findings suggest that ENA-78 is an important angiogenic factor in human NSCLC.

Dyspnea differentiation index: A new method for the rapid separation of cardiac vs pulmonary dyspnea.

STUDY OBJECTIVE: To assess the utility of a new parameter in the differentiation of dyspnea of cardiac origin from dyspnea of pulmonary origin. METHODS: The peak expiratory flow (PEF) rate and the partial pressure of oxygen in arterial blood (PaO(2)) were measured in 71 patients with the chief complaint of dyspnea. The patients were treated in the hospital, and the final diagnosis (cardiac or pulmonary) of the cause of dyspnea was made at discharge. We defined a new measure, the dyspnea differentiation index (DDI), as (PEF x PaO(2))/1,000. We performed a receiver operating characteristic (ROC) curve analysis of the data to define the measure that best distinguished cardiac from pulmonary dyspnea. The curves also allowed us to establish an optimal cut-off point to distinguish between cardiac and pulmonary dyspnea. RESULTS: Patients with pulmonary dyspnea had a significantly lower mean PEF than patients with cardiac dyspnea (144 +/- 66 vs 267 +/- 97 L/min, respectively; p < 0.001). They also had a lower DDI than patients with cardiac dyspnea (8.4 +/- 4.0 vs 18.4 +/- 7.9 L-mm/min, respectively; p < 0.001). These two measures, PEF and DDI, also best distinguished pulmonary from cardiac dyspnea. PEF was able to diagnose the correct cause of dyspnea in 72% of patients, and DDI was correct in 79% of patients. This compares favorably to the performance of the emergency department physicians, who were able to predict the correct diagnosis in only 69% of patients. CONCLUSION: These results demonstrate that the PEF by itself is useful in differentiating between cardiac and pulmonary causes of dyspnea, but that the calculation of DDI is superior in this regard.

Cephalosporin-resistant pneumococcal pneumonia: does it, affect outcome?

STUDY OBJECTIVES: Penicillin resistance has been reported in various studies to have no impact on the outcome of pneumococcal pneumonia. However, the importance of cephalosporin resistance has not been systematically studied. We conducted an analysis of patients with high-level cephalosporin-resistant Streptococcus pneumoniae pneumonia (H-CRSPP). DESIGN: Retrospective matched, case-control study. SETTING: Two inner-city academic hospitals. PATIENTS: Twenty-six patients with H-CRSPP admitted to the hospital between 1995 and 1999 were identified. Each patient was matched with two controls with cephalosporin-sensitive but oxacillin-resistant pneumococcal pneumonia admitted during the same time period. Matching was done based on pneumonia severity of illness index (PSI) and for other factors. INTERVENTIONS: None. MEASUREMENTS AND RESULTS: We evaluated a number of outcomes including mortality length of stay in the hospital, and time to respond to treatment. Patients with H-CRSPP took longer to respond to treatment (6.5 +/- 0.9 days vs 4.1 +/- 0.7 days, P=0.05) and had a longer length of stay in hospital (15.4 +/- 2.2 days vs 92 +/- 1.6 days, P=0.02). None of the other outcomes were different between the two groups. CONCLUSIONS: Overall, we have found that the presence of cephalosporin resistance does impact the course of pneumococcal pneumonia.

RETRACTED: A shorter 146Sm half-life measured and implications for 146Sm-142Nd chronology in the solar system.

The extinct p-process nuclide (146)Sm serves as an astrophysical and geochemical chronometer through measurements of isotopic anomalies of its α-decay daughter (142)Nd. Based on analyses of (146)Sm/(147)Sm α-activity and atom ratios, we determined the half-life of (146)Sm to be 68 ± 7 (1σ) million years, which is shorter than the currently used value of 103 ± 5 million years. This half-life value implies a higher initial (146)Sm abundance in the early solar system, ((146)Sm/(144)Sm)(0) = 0.0094 ± 0.0005 (2σ), than previously estimated. Terrestrial, lunar, and martian planetary silicate mantle differentiation events dated with (146)Sm-(142)Nd converge to a shorter time span and in general to earlier times, due to the combined effect of the new (146)Sm half-life and ((146)Sm/(144)Sm)(0) values.

Impact of active surveillance on meticillin-resistant Staphylococcus aureus transmission and hospital resource utilisation.

The utility of active surveillance cultures (ASCs) for meticillin-resistant Staphylococcus aureus (MRSA) has been a controversial aspect of infection prevention. This prospective cohort study analyses the effect of ASCs for MRSA on hospital-acquired infections in a tertiary care hospital (hospital 1) and a community-based hospital (hospital 2). Both hospitals have high MRSA prevalence and are part of a large healthcare system in southeastern Michigan. Hospital-acquired infections in the intensive care unit (ICU) and in the rest of the hospital were compared before and after the implementation of ASCs in the ICUs. Patients in hospital 1 with evidence of MRSA colonisation from ASCs were placed in contact isolation during their stay in the ICU; patients from hospital 2 remained in contact isolation throughout their hospital stay. Prevalence of MRSA colonisation on admission to the ICU was 23% and 13% in hospitals 1 and 2, respectively. Average incidence of new colonisation during the study period was 1.85 per 1000 patient-days and 3.47 per 1000 patient-days in hospitals 1 and 2, respectively. A decrease in ventilator-associated pneumonia (VAP) occurred in both hospitals, whereas decrease in hospital-wide nosocomial MRSA infection was demonstrated only in hospital 2. We conclude that, in addition to standard infection prevention initiatives, ASC with contact precautions can be effective in reducing the incidence of VAP and nosocomial MRSA infection in healthcare communities with endemic MRSA.

The attributable mortality and costs of primary nosocomial bloodstream infections in the intensive care unit.

Primary nosocomial bloodstream infection (BSI) is a common occurrence in the intensive care unit (ICU) and is associated with a crude mortality of 31.5 to 82.4%. However, an accurate estimate of the attributable mortality has been limited because of confounding by severity of illness. We undertook this study to assess the attributable mortality and costs associated with an episode of BSI. Infected patients were defined as those who had an episode of BSI during the study period. Uninfected control subjects were matched to the infected patients based upon a number of factors, including predicted mortality on the day prior to infection. The main outcome measures were crude ICU mortality, length of stay, and costs. We found no difference in the crude mortality for the infected and the uninfected patients (35.3 and 30.9%, respectively, p = 0.51). However, among survivors, the patients with nosocomial bloodstream infections did have excess length of stay (mean, 10 d; median, 5 d; p = 0.007) and increased direct costs (mean difference, $34,508; p = 0.008). After matching for severity of illness, we could not detect an association between primary nosocomial bloodstream infections and increased ICU mortality. We did find that primary nosocomial bloodstream infections increased ICU length of stay and costs.