150 research outputs found
Polarisation signatures in radio for inclined cosmic-ray induced air-shower identification
Autonomous radio-detection, i.e., detection of air-showers with standalone
radio arrays, is one of the major technical challenges to overcome for the next
generation astroparticle detectors. In this context, we study polarisation
signatures of simulated radio signals to perform an identification of the
associated air-showers initiated by cosmic-rays and neutrinos. We compare the
two sources of radio emission (the charge excess and geomagnetic) and show that
the former is almost negligible for inclined (zenith angle )
cosmic-ray air-showers. This provides an efficient background rejection
criterion at the DAQ level, based on the projection of the total electric field
along the direction of the local magnetic field. This relevant quantity can be
easily computed -- even in an online treatment -- for antennas measuring three
orthogonal polarisations. Independently of the experimental antenna layout, we
estimate that assuming a random polarisation of noise events, a rejection from
(for a non favorable detector location) to (for a
favorable location) of the noise induced events and a trigger efficiency of 87%
(93%) with a () trigger threshold level should be
achievable. We also show that neutrino-induced showers present a charge excess
to geomagnetic signal ratio up to times higher than for cosmic ray
showers. Although this characteristic makes the identification of
neutrino-induced showers challenging via the method developed here, it provides
an efficient criterion to perform an offline discrimination between cosmic-ray
and neutrino primaries. The stronger charge excess emission will also help the
reconstruction of air-shower parameters, such as the core position.Comment: 19 pages, 26 figures, 3 tables. Accepted in Astroparticle Physic
Imaging in pulmonary hypertension: Focus on the role of echocardiography
SummaryPatients with pulmonary hypertension must be evaluated using a multimodality approach to ensure a correct diagnosis and basal evaluation as well as a prognostic assessment. Beyond the assessment of pulmonary pressures, the echocardiographical examination allows the evaluation of right ventricular adaptation to elevated afterload. Numbers of variables are commonly used in the assessment of the pulmonary hypertension patient in order to detect changes in right heart geometry, right-to-left interaction and right ventricular dysfunction. Whereas an isolated change in one echocardiographical variable is not meaningful, multiple echocardiographical variable modifications together provide accurate information. In this review, we will link pulmonary hypertension pathophysiological changes with echocardiographical indices and describe the clinical implications of echocardiographical findings
Epidemiology, Prognosis, and Evolution of Management of Septic Shock in a French Intensive Care Unit: A Five Years Survey
Purpose. To evaluate the epidemiology, prognosis, and management of septic shock patients hospitalized in our intensive care unit (ICU). Materiel and Methods. Five-year monocenter observational study including 320 patients. Results. ICU mortality was 54.4%. Independent mortality risk factors were mechanical ventilation (OR = 4.97), Simplify Acute Physiology Score (SAPS) II > 60 (OR = 4.28), chronic alcoholism (OR = 3.38), age >65 years (OR = 2.65), prothrombin ratio <40% (OR = 2.37), and PaO2/FiO2 ratio <150 (OR = 1.91). These six mortality risk factors recovered allow screening immediately septic shock patients with a high mortality risk. Morbidity improved with time (diminution of septic shock complications, increase of the number of days alive free from mechanical ventilation and vasopressors on day 28), concomitant to an evolution of the management (earlier institution of all replacement and medical therapies and more initial volume expansion). There was no difference in mortality.
Conclusion. Our study confirms a high mortality rate in septic shock patients despite a new approach of treatment
Validation of a Prediction Rule for Prognosis of Severe Community-Acquired Pneumonia
In a previous study, we developed a prognostic prediction rule, based on nine prognostic variables, capable to estimate and to adjust the mortality rate of patients admitted in intensive care unit for severe community-acquired pneumonia. A prospective multicenter study was undertaken to evaluate the performance of this rule. Five hundred eleven patients, over a 7-year period, were studied. The ICU mortality rate was 29.0%. In the 3 initial risk classes, we observed significantly increasing mortality rates (8.2% in class I, 22.8% in class II and 65.0% in class III) (p<0.001). Within each initial risk class, the adjustment risk score identified subclasses exhibiting significantly different mortality rates: 3.9% and 33.3% in class I; 3.1%, 12.9% and 63.3% in class II; and 55.8% and 82.5% in class III. Compared with mortality rates predicted by our previous study, only a few significant differences were observed. Our results demonstrate the performance and reproductibility of this prognostic prediction rule
Risk factors for post-ICU red blood cell transfusion: a prospective study
INTRODUCTION: Factors predictive of the need for red blood cell (RBC) transfusion in the intensive care unit (ICU) have been identified, but risk factors for transfusion after ICU discharge are unknown. This study aims identifies risk factors for RBC transfusion after discharge from the ICU. METHODS: A prospective, monocentric observational study was conducted over a 6-month period in a 24-bed medical ICU in a French university hospital. Between June and December 2003, 550 critically ill patients were consecutively enrolled in the study. RESULTS: A total of 428 patients survived after treatment in the ICU; 47 (11% of the survivors, 8.5% of the whole population) required RBC transfusion within 7 days after ICU discharge. Admission for sepsis (odds ratio [OR] 341.60, 95% confidence interval [CI] 20.35–5734.51), presence of an underlying malignancy (OR 32.6, 95%CI 3.8–280.1), female sex (OR 5.4, 95% CI 1.2–24.9), Logistic Organ Dysfunction score at ICU discharge (OR 1.45, 95% CI 1.1–1.9) and age (OR 1.06, 95% CI 1.02–1.12) were independently associated with RBC transfusion after ICU stay. Haemoglobin level at discharge predicted the need for delayed RBC transfusion. Use of vasopressors (OR 0.01, 95%CI 0.001–0.17) and haemoglobin level at discharge from the ICU (OR 0.02, 95% CI 0.007–0.09; P < 0.001) were strong independent predictors of transfusion of RBC 1 week after ICU discharge. CONCLUSION: Sepsis, underlying conditions, unresolved organ failures and haemoglobin level at discharge were related to an increased risk for RBC transfusion after ICU stay. We suggest that strategies to prevent transfusion should focus on homogeneous subgroups of patients and take into account post-ICU needs for RBC transfusion
Design of metal oxide nanoparticles: Control of size, shape, crystalline structure and functionalization by aqueous chemistry
Cardiogenic shock due to reverse takotsubo syndrome triggered by multiple sclerosis brainstem lesions: a case report and mini review
BackgroundTakotsubo syndrome (TTS) is mainly characterized by chest pain, left ventricular dysfunction, ST-segment deviation on electrocardiogram (ECG) and elevated troponins in the absence of obstructive coronary artery disease. Diagnostic features include left ventricular systolic dysfunction shown on transthoracic echocardiography (TTE) with wall motion abnormalities, generally with the typical “apical ballooning” pattern. In very rare cases, it involves a reverse form which is characterized by basal and mid-ventricular severe hypokinesia or akinesia, and sparing of the apex. TTS is known to be triggered by emotional or physical stressors. Recently, multiple sclerosis (MS) has been described as a potential trigger of TTS, especially when lesions are located in the brainstem.Case summaryWe herein report the case of a 26-year-old woman who developed cardiogenic shock due to reverse TTS in the setting of MS. After being admitted for suspected MS, the patient presented with rapidly deteriorating clinical condition, with acute pulmonary oedema and hemodynamic collapse, requiring mechanical ventilation and aminergic support. TTE found a severely reduced left ventricular ejection fraction (LVEF) of 20%, consistent with reverse TTS (basal and mid ventricular akinesia, apical hyperkinesia). Cardiac magnetic resonance imaging (MRI) performed 4 days later showed myocardial oedema in the mid and basal segments on T2-weighted imaging, with partial recovery of LVEF (46%), confirmed the diagnosis of TTS. In the meantime, the suspicion of MS was also confirmed, based on cerebral MRI and cerebral spinal fluid analyses, with a final diagnosis of reverse TTS induced by MS. High-dose intravenous corticotherapy was initiated. Subsequent evolution was marked by rapid clinical improvement, as well as normalization of LVEF and segmental wall-motion abnormalities.ConclusionOur case is an example of the brain-heart relationship: it shows how neurologic inflammatory diseases can trigger a cardiogenic shock due to TTS, with potentially serious outcomes. It sheds light on the reverse form, which, although rare, has already been described in the setting of acute neurologic disorders. Only a handful of case reports have highlighted MS as a trigger of reverse TTS. Finally, through an updated systematic review, we highlight the unique features of patients with reversed TTS triggered by MS
Control-FREEC: a tool for assessing copy number and allelic content using next-generation sequencing data
Summary: More and more cancer studies use next-generation sequencing (NGS) data to detect various types of genomic variation. However, even when researchers have such data at hand, single-nucleotide polymorphism arrays have been considered necessary to assess copy number alterations and especially loss of heterozygosity (LOH). Here, we present the tool Control-FREEC that enables automatic calculation of copy number and allelic content profiles from NGS data, and consequently predicts regions of genomic alteration such as gains, losses and LOH. Taking as input aligned reads, Control-FREEC constructs copy number and B-allele frequency profiles. The profiles are then normalized, segmented and analyzed in order to assign genotype status (copy number and allelic content) to each genomic region. When a matched normal sample is provided, Control-FREEC discriminates somatic from germline events. Control-FREEC is able to analyze overdiploid tumor samples and samples contaminated by normal cells. Low mappability regions can be excluded from the analysis using provided mappability tracks
Study of Human RIG-I Polymorphisms Identifies Two Variants with an Opposite Impact on the Antiviral Immune Response
International audienceBACKGROUND: RIG-I is a pivotal receptor that detects numerous RNA and DNA viruses. Thus, its defectiveness may strongly impair the host antiviral immunity. Remarkably, very little information is available on RIG-I single-nucleotide polymorphisms (SNPs) presenting a functional impact on the host response. METHODOLOGY/PRINCIPAL FINDINGS: Here, we studied all non-synonymous SNPs of RIG-I using biochemical and structural modeling approaches. We identified two important variants: (i) a frameshift mutation (P(229)fs) that generates a truncated, constitutively active receptor and (ii) a serine to isoleucine mutation (S(183)I), which drastically inhibits antiviral signaling and exerts a down-regulatory effect, due to unintended stable complexes of RIG-I with itself and with MAVS, a key downstream adapter protein. CONCLUSIONS/SIGNIFICANCE: Hence, this study characterized P(229)fs and S(183)I SNPs as major functional RIG-I variants and potential genetic determinants of viral susceptibility. This work also demonstrated that serine 183 is a residue that critically regulates RIG-I-induced antiviral signaling
CD63-GPC1-Positive Exosomes Coupled with CA19-9 Offer Good Diagnostic Potential for Resectable Pancreatic Ductal Adenocarcinoma
Tumor-released extracellular vesicles (EVs) contain tumor-specific cargo distinguishing them from healthy EVs, and making them eligible as circulating biomarkers. Glypican 1 (GPC1)-positive exosome relevance as liquid biopsy elements is still debated. We carried out a prospective study to quantify GPC1-positive exosomes in sera from pancreatic ductal adenocarcinoma (PDAC) patients undergoing up-front surgery, as compared to controls including patients without cancer history and patients displaying pancreatic preneoplasic lesions. Sera were enriched in EVs, and exosomes were pulled down with anti-CD63 coupled magnetic beads. GPC1-positive bead percentages determined by flow cytometry were significantly higher in PDAC than in the control group. Diagnosis accuracy reached 78% (sensitivity 64% and specificity 90%), when results from peripheral and portal blood were combined. In association with echo-guided-ultrasound-fine-needle-aspiration (EUS-FNA) negative predictive value was 80% as compared to 33% for EUS-FNA only. This approach is clinically relevant as a companion test to the already available diagnostic tools, since patients with GPC1-positive exosomes in peripheral blood showed decreased tumor free survival
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