Observation of New Properties of Secondary Cosmic Rays Lithium, Beryllium, and Boron by the Alpha Magnetic Spectrometer on the International Space Station

We report on the observation of new properties of secondary cosmic rays Li, Be, and B measured in the rigidity (momentum per unit charge) range 1.9 GV to 3.3 TV with a total of 5.4×10^{6} nuclei collected by AMS during the first five years of operation aboard the International Space Station. The Li and B fluxes have an identical rigidity dependence above 7 GV and all three fluxes have an identical rigidity dependence above 30 GV with the Li/Be flux ratio of 2.0±0.1. The three fluxes deviate from a single power law above 200 GV in an identical way. This behavior of secondary cosmic rays has also been observed in the AMS measurement of primary cosmic rays He, C, and O but the rigidity dependences of primary cosmic rays and of secondary cosmic rays are distinctly different. In particular, above 200 GV, the secondary cosmic rays harden more than the primary cosmic rays.

Observation of the Identical Rigidity Dependence of He, C, and O Cosmic Rays at High Rigidities by the Alpha Magnetic Spectrometer on the International Space Station

We report the observation of new properties of primary cosmic rays He, C, and O measured in the rigidity (momentum/charge) range 2 GV to 3 TV with 90×10^{6} helium, 8.4×10^{6} carbon, and 7.0×10^{6} oxygen nuclei collected by the Alpha Magnetic Spectrometer (AMS) during the first five years of operation. Above 60 GV, these three spectra have identical rigidity dependence. They all deviate from a single power law above 200 GV and harden in an identical way.

Evaluation of Renal Function in Patients Undergoing Lung Transplantation

BACKGROUND

Acute kidney injury and chronic kidney failure are serious complications after lung transplantation. Glomerular filtration rate (GFR) is the primary indicator of renal function. Several equations have been proposed to evaluate the estimated GFR (eGFR). We compared three different equations to determine which has the better correlation with the development of acute and chronic renal failure in lung recipients.

METHODS

Twenty-two patients with a mean age of 54.4 ± 8.5 years underwent lung transplantation from 2010 to 2015. Thirteen (59%) had pulmonary fibrosis, 7 (32%) emphysema, 1 (4.5%) bronchiectasis, and 1 (4.5%) lymphangioleiomyomatosis. In all patients, eGFR was measured preoperatively using Cockcroft-Gault (CG), Modification of Diet in Renal Disease (MDRD), and Levey's Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equations. In 20 patients (90%) eGFR was calculated at 1, 3, and 6 months.

RESULTS

According to CKD-EPI and MDRD, eight patients (36.3%) had preoperative reduction in eGFR, whereas 6 patients (27.2%) had preoperative reduction according to the CG (P = .04). The mean values were higher for the CG (103.2 vs. 102 vs. 94.4). Five patients (22.7%) developed perioperative acute renal failure requesting a dialysis treatment; four of these showed a preoperative eGFR to the highest CG (P = .05). At 1 and 6 months after lung transplantation, the CG, MDRD and CKD-EPI eGFR values were, respectively, 86.6, 84.1 and 76.6 mL/min/1.73m² and 75.8, 72.7, and 72.3 mL/min/1.73m². CKD-EPI eGFR values are more predictable than the other equations of AKI.

CONCLUSIONS

Preoperative assessment of eGFR using the MDRD and CKD-EPI seems to correlate better than the CG to the prediction of acute renal failure, whereas for the chronic form the three equations seem equivalent.

Biochemical stress evaluation after medial parapatellar and subvastus approach in total knee replacement

INTRODUCTION

Even if different surgical approaches for total knee arthroplasty are well known since decades, the standard medial parapatellar incision remains the most common one; general agreement about significant advantages with minimally invasive techniques is lacking. Furthermore, the surgical stress effect on the organism has always been analyzed through blood inflammatory parameters. This study aim was to compare the standard and subvastus approaches, using the salivary cortisol in particular as measure for systemic surgery-related stress.

METHODS

Fifteen operations were performed in a consecutive series; clinical (Knee Society Knee Scoring System., a questionnaire score, range of motion, tourniquet time, intra-operative bleeding) and biochemical factors (salivary and hematic cortisol, C-reactive protein, muscular creatine phosphokinase levels) were evaluated. The final follow-up was at two months after the operation.

RESULTS

No significant differences were observed in most of the parameters; however, the subvastus group had a sharper and earlier functional improvement trend than the standard one. On the other side, it increased the CPK levels significantly.

CONCLUSIONS

In our experience, the medial subvastus approach, firstly associated with greater surgical stress, has then been characterized by a more favorable functional improvement trend. Moreover, the salivary cortisol measurement has proved to be a non-invasive and reliable method to evaluate the systemic surgery-related stress.

Prevalence of alcohol and other drugs in injured drivers and their association with clinical outcomes

OBJECTIVE

Driving under the influence of alcohol or drugs is a risk factor for motor vehicle accidents (MVAs). This issue has become an increasing concern for the governments of many European and North American countries, thereby encouraging the adoption of preventive policies. The aim of this study was to investigate the associations between major clinical outcomes and alcohol or drug abuse among drivers involved in MVAs who were referred to an Italian Emergency Department.

PATIENTS AND METHODS

The study population consisted of consecutive injured drivers who were admitted to the Emergency Department following an MVA during a period of one year. The patients' blood alcohol concentrations (BACs) and the presence of the most common drugs of abuse [amphetamine, methamphetamine, methylenedioxymethamphetamine (MDMA), barbiturates, benzodiazepines, benzoylecgonine (cocaine main metabolite), cannabinoids, methadone, and opiates)] were determined and evaluated in association with major clinical outcomes and demographic data.

RESULTS

Overall, 347 injured drivers were enrolled. Of the 347 enrolled patients, 164 (47.3%) had a positive BAC (greater than 5 mg/dL). A subgroup of 107 injured drivers was also screened for drugs of abuse. Thirty-seven of these subjects (34.5%) were positive for at least one drug. A statistically significant association was found between BAC and triage at admission (p<0.01), hospitalization (p<0.01), and lesions of internal organs (p=0.04).

CONCLUSIONS

The results of this study show that a significant proportion of injured drivers had detectable levels of BAC and/or illegal drugs. Positive BACs were significantly associated with worse clinical outcomes. These findings suggest that the implementation of methods to prevent alcohol and drug abuse is of paramount importance in the effort to reduce the rates of MVAs and their dramatic consequences.

Precision Measurement of the Boron to Carbon Flux Ratio in Cosmic Rays from 1.9 GV to 2.6 TV with the Alpha Magnetic Spectrometer on the International Space Station

Knowledge of the rigidity dependence of the boron to carbon flux ratio (B/C) is important in understanding the propagation of cosmic rays. The precise measurement of the B/C ratio from 1.9 GV to 2.6 TV, based on 2.3 million boron and 8.3 million carbon nuclei collected by AMS during the first 5 years of operation, is presented. The detailed variation with rigidity of the B/C spectral index is reported for the first time. The B/C ratio does not show any significant structures in contrast to many cosmic ray models that require such structures at high rigidities. Remarkably, above 65 GV, the B/C ratio is well described by a single power law R^{Δ} with index Δ=-0.333±0.014(fit)±0.005(syst), in good agreement with the Kolmogorov theory of turbulence which predicts Δ=-1/3 asymptotically.

Pulmonary tuberculosis followed by sarcoidosis in an HIV-infected patient: A case report and a simplified diagnostic flowchart for diagnosis and treatment of sarcoidosis

The diagnosis of sarcoidosis in a patient living with HIV infection is an uncommon event and a challenge for clinicians. Clinical manifestations are variable and fluctuating depending to adherence to ARV therapy and to the level of CD4 count. We analyze here one chronic case in which sarcoidosis appeared clinically two years after pulmonary tuberculosis. The course of the disease was influenced and prolonged by frequent interruptions of antiretroviral therapy. Moreover the diagnosis and the decision to treat have been delayed by the need of exclusion of other pathologies, principally tuberculosis reactivation/reinfection, other mycobacterial diseases, hematologic malignancies. We propose a simplified flowchart for diagnosis and follow up of sarcoidosis, which may also be applied to patients with HIV infection. Diagnosis of latent tuberculosis infection (LTBI) may be difficult in these patients, because the immunological paradox of sarcoidosis. For this reason, following exclusion of active tuberculosis, we advise to submit all sarcoidosis patients to IPT (isoniazid preventive therapy), when immunosuppressive therapy is started.

Antiproton Flux, Antiproton-to-Proton Flux Ratio, and Properties of Elementary Particle Fluxes in Primary Cosmic Rays Measured with the Alpha Magnetic Spectrometer on the International Space Station

A precision measurement by AMS of the antiproton flux and the antiproton-to-proton flux ratio in primary cosmic rays in the absolute rigidity range from 1 to 450 GV is presented based on 3.49×10^{5} antiproton events and 2.42×10^{9} proton events. The fluxes and flux ratios of charged elementary particles in cosmic rays are also presented. In the absolute rigidity range ∼60 to ∼500  GV, the antiproton p[over ¯], proton p, and positron e^{+} fluxes are found to have nearly identical rigidity dependence and the electron e^{-} flux exhibits a different rigidity dependence. Below 60 GV, the (p[over ¯]/p), (p[over ¯]/e^{+}), and (p/e^{+}) flux ratios each reaches a maximum. From ∼60 to ∼500  GV, the (p[over ¯]/p), (p[over ¯]/e^{+}), and (p/e^{+}) flux ratios show no rigidity dependence. These are new observations of the properties of elementary particles in the cosmos.

Precision Measurement of the Helium Flux in Primary Cosmic Rays of Rigidities 1.9 GV to 3 TV with the Alpha Magnetic Spectrometer on the International Space Station

Knowledge of the precise rigidity dependence of the helium flux is important in understanding the origin, acceleration, and propagation of cosmic rays. A precise measurement of the helium flux in primary cosmic rays with rigidity (momentum/charge) from 1.9 GV to 3 TV based on 50 million events is presented and compared to the proton flux. The detailed variation with rigidity of the helium flux spectral index is presented for the first time. The spectral index progressively hardens at rigidities larger than 100 GV. The rigidity dependence of the helium flux spectral index is similar to that of the proton spectral index though the magnitudes are different. Remarkably, the spectral index of the proton to helium flux ratio increases with rigidity up to 45 GV and then becomes constant; the flux ratio above 45 GV is well described by a single power law.

Bactericidal and synergistic activity of double-carbapenem regimen for infections caused by carbapenemase-producing Klebsiella pneumoniae

Available therapeutic options against carbapenem-resistant Klebsiella pneumoniae (CR-Kp) are limited because of the high level of resistance to other antimicrobial classes including polymyxins. The double-carbapenem regimen has been recently considered a possible therapeutic strategy. In the present study, we evaluated the in vitro bactericidal and synergistic activity of a double-carbapenem regimen consisting of ertapenem plus high-dose meropenem in a series of patients with healthcare-associated CR-Kp infections in whom the use of colistin was not indicated because of potential nephrotoxicity and/or resistance. In vitro synergy was evaluated using checkerboard and killing studies. A total of 15 patients were included in the study, with sepsis, severe sepsis and septic shock found in two (13.3%), five (33.3%) and one (6.7%) patients, respectively. Overall, the clinical/microbiological response was 12/15 (80%). Synergy was observed in 11/14 (78.6%) isolates using the checkerboard method whereas in killing studies 12/14 (85.7%) and 14/14 (100%) strains were synergistic and bactericidal at 24 h at concentrations of 1 × MIC MEM+1 × MIC ERT and 2 × MEM+1 × MIC ERT, respectively, with a significant decrease of log CFU/mL compared with other combinations (p <0.0001). The double-carbapenem regimen showed clinical and in vitro effectiveness in patients with CR-Kp infections.

Precision Measurement of the Proton Flux in Primary Cosmic Rays from Rigidity 1 GV to 1.8 TV with the Alpha Magnetic Spectrometer on the International Space Station

A precise measurement of the proton flux in primary cosmic rays with rigidity (momentum/charge) from 1 GV to 1.8 TV is presented based on 300 million events. Knowledge of the rigidity dependence of the proton flux is important in understanding the origin, acceleration, and propagation of cosmic rays. We present the detailed variation with rigidity of the flux spectral index for the first time. The spectral index progressively hardens at high rigidities.

Precision Measurement of the (e^{+}+e^{-}) Flux in Primary Cosmic Rays from 0.5 GeV to 1 TeV with the Alpha Magnetic Spectrometer on the International Space Station

We present a measurement of the cosmic ray (e^{+}+e^{-}) flux in the range 0.5 GeV to 1 TeV based on the analysis of 10.6 million (e^{+}+e^{-}) events collected by AMS. The statistics and the resolution of AMS provide a precision measurement of the flux. The flux is smooth and reveals new and distinct information. Above 30.2 GeV, the flux can be described by a single power law with a spectral index γ=-3.170±0.008(stat+syst)±0.008(energy scale).

Electron and positron fluxes in primary cosmic rays measured with the alpha magnetic spectrometer on the international space station

Precision measurements by the Alpha Magnetic Spectrometer on the International Space Station of the primary cosmic-ray electron flux in the range 0.5 to 700 GeV and the positron flux in the range 0.5 to 500 GeV are presented. The electron flux and the positron flux each require a description beyond a single power-law spectrum. Both the electron flux and the positron flux change their behavior at ∼30  GeV but the fluxes are significantly different in their magnitude and energy dependence. Between 20 and 200 GeV the positron spectral index is significantly harder than the electron spectral index. The determination of the differing behavior of the spectral indices versus energy is a new observation and provides important information on the origins of cosmic-ray electrons and positrons.

High statistics measurement of the positron fraction in primary cosmic rays of 0.5-500 GeV with the alpha magnetic spectrometer on the international space station

A precision measurement by AMS of the positron fraction in primary cosmic rays in the energy range from 0.5 to 500 GeV based on 10.9 million positron and electron events is presented. This measurement extends the energy range of our previous observation and increases its precision. The new results show, for the first time, that above ∼200  GeV the positron fraction no longer exhibits an increase with energy.