Calculation code for helically coiled heat recovery boilers

This paper describes a calculation code developed for helically coiled heat recovery boilers fed with exhaust gases from internal combustion engines, gas turbines or industrial processes. The code carries out the thermal rating calculation of the boiler by means of a one-dimensional model applicable to either water or thermal oil heating or steam generation in a once-through configuration. The paper is focused on the first case, in which cold fluid phase-change does not occur, and illustrates how the rating program can be helpful to improve the boiler design with respect to the current standard, allowing a reduction of several percentage points in the calculated heat transfer area (and correspondingly weight and material cost) required for a given duty. © 2013 The Authors

Vaccines against coronaviruses: The state of the art

The emerging epidemic caused by the new coronavirus SARS-CoV-2 represents the most important socio-health threat of the 21st century. The high contagiousness of the virus, the strong impact on the health system of the various countries and the absence to date of treatments able to improve the prognosis of the disease make the introduction of a vaccine indispensable, even though there are currently no approved human coronavirus vaccines. The aim of the study is to carry out a review of the medical literature concerning vaccine candidates for the main coronaviruses responsible for human epidemics, including recent advances in the development of a vaccine against COVID-19. This extensive review carried out on the vaccine candidates of the main epidemic coronaviruses of the past has shown that the studies in animal models suggest a high efficacy of potential vaccines in providing protection against viral challenges. Similar human studies have not yet been carried out, as the main trials are aimed at assessing mainly vaccine safety and immunogenicity. Whereas the severe acute respiratory syndrome (SARS-CoV) epidemic ended almost two decades ago and the Middle East respiratory syndrome (MERS-CoV) epidemic is now better controlled, as it is less contagious due to the high lethality of the virus, the current SARS-CoV-2 pandemic represents a problem that is certainly more compelling, which pushes us to accelerate the studies not only for the production of vaccines but also for innovative pharmacological treatments. SARS-CoV-2 vaccines might come too late to affect the first wave of this pandemic, but they might be useful if additional subsequent waves occur or in a post-pandemic perspective in which the virus continues to circulate as a seasonal virus

Stones in hydrocalyx: Endoscopic treatment in a complex case

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The International development of PROQOL-HCV: An instrument to assess the health-related quality of life of patients treated for Hepatitis C virus

Background Hepatitis C virus (HCV) compromises Health-related Quality of Life (HRQL) with detriments to Physical, Mental and Social health domains. Treatment with interferon and ribavirin is associated with side effects which further impair HRQL. New treatments appear potent, effective and tolerable. However, Patient Reported Outcomes instruments that capture the impact on HRQL for people with hepatitis C are largely non-specific and will be needed in the new treatment era. Therefore, we developed a conceptually valid multidimensional model of HCV-specific quality of life and pilot survey instrument, the Patient Reported Outcome Quality of Life survey for HCV (PROQOL-HCV). Methods HCV patients from France (n = 30), Brazil (n = 20) and Australia (n  = 20) were interviewed to investigate HCV-HRQL issues raised in the scientific literature and by treatment specialists. Interviews were recorded, transcribed and translated into English and French. Results Fifteen content dimensions were derived from the qualitative analysis, refined and fitted to four domains: (1) Physical Health included: fatigue, pain, sleep, sexual impairment and physical activity; (2) Mental Health: psychological distress, psychosocial impact, and cognition; (3) Social Health: support, stigma, social activity, substance use; (4) Treatment: management, side effects, and fear of treatment failure. The impact of some dimensions extended beyond their primary domain including: physical activity, cognition, sleep, sexual impairment, and the three treatment dimensions. A bank of 300 items was constructed to reflect patient reports and, following expert review, reduced to a 72-item pilot questionnaire. Conclusion We present a conceptually valid multidimensional model of HCV-specific quality of life and the pilot survey instrument, PROQOL-HCV. The model is widely inclusive of the experience of hepatitis C and the first to include the treatment dimension

Liver fibrosis staging using supersonic shear imaging : a clinical study on 142 patients

International audienceI. Background, Motivation and ObjectiveFibrosis staging can be assessed by a rough estimation of the liver stiffness averaged along an ultrasonic A-line. Providing a complete 2D map of liver stiffness would thus be of great clinical interest for the diagnosis of hepatic fibrosis and help prevent upcoming cirrhosis. However, such measurement requires both a quantitative value of shear elasticity and a great precision to discriminate between different fibrosis levels. Beyond the scope of non-invasive fibrosis quantification, it is also envisioned that quantitative elasticity imaging of liver will have potential interest for liver cancer diagnosis. In this work, the Supersonic Shear Imaging technique (SSI) is proposed to map the in vivo viscoelastic parameters of liver on patients with hepatitis C and derive a mean elasticity of liver tissues. The results are compared to biological tests (Fib4, Apri, Forns) and Fibroscan® measurements. II. Statement of Contribution / MethodsThe SSI technique is based on the radiation force induced by a conventional ultrasonic probe to generate a planar shear wave deep into tissues. The shear wave propagation throughout the medium is caught in real time thanks to an ultrafast ultrasound scanner (up to 5000 frames/s). Using modified sequences and post-processing, this technique is implemented on curved arrays in order to get a larger field of view of liver tissues. A study on 150 HCV patients with different fibrosis stages F has been conducted in order to investigate the accuracy of the technique (F ϵ [0;4]). Quantitative maps of liver elasticity are produced for each volunteer with a linear and a curved array. III. ResultsB-mode images of 120x75 mm² and corresponding elasticity maps are obtained using a 2.5 MHz curved ultrasonic probe with a good reproducibility and accuracy. The shear wave phase velocity dispersion is also calculated. This study shows a good correlation between the values obtained by SSI and the fibrosis levels diagnosed by biological tests (p-index 0.9 for F>3 and Y> 0.8 for F>2). Results are also compared (r2 > 0.92) to the Fibroscan® elasticity measurement by fitting the velocity dispersion curves obtained by SSI at 50 Hz.IV. Discussion and ConclusionsThis real-time elasticity mapping using an ultrasonic curved probe offers better signal to noise ratio than linear arrays and a larger area in the patient's liver (13.3±2.8 cm² estimation area). This gives more confidence on the accuracy of the diagnosis of the fibrosis stage. Furthermore, the elasticity parameters obtained with SSI give access to the shear wave group velocity and the phase velocity. As a consequence, the SSI assessment of liver stiffness could potentially give more information on the viscoelasticity properties of the liver

Primary liver cancer is more aggressive in HIV-HCV coinfection than in HCV infection. A prospective study (ANRS CO13 Hepavih and CO12 Cirvir)

OBJECTIVE: Since HAART, primary liver cancer has emerged as an increasing cause of morbidity and mortality in patients with HIV infection. Our aim was to compare characteristics and outcome of primary liver cancer according to HIV status in HCV cirrhotic patients submitted to periodic ultrasonographic surveillance. METHODS: All patients with primary liver cancer and cirrhosis were selected from two prospective cohorts (ANRS CO12 Cirvir, viral cirrhosis, n=1081; ANRS CO13 Hepavih, HIV-HCV coinfection, n=1175). Cirrhosis was diagnosed by liver biopsy in monoHCV group and biopsy and/or non-invasive tests in HIV-HCV group. Ultrasonographic surveillance was performed every 6 months. Diagnosis of primary liver cancer was established according to EASL-AASLD guidelines. RESULTS: Primary liver cancer was diagnosed in 32 patients, 16 in each group, and corresponded to hepatocellular carcinoma in all except for two cholangiocarcinomas in HIV-HCV patients. Ultrasonographic follow-up was similar (median time since last ultrasonographic without focal lesion: 237 days in HIV-HCV group (n=12) versus 208 days in HCV group, NS). At primary liver cancer diagnosis HIV-HCV patients were markedly younger (48 vs. 60 yrs, P<0.001), primary liver cancer was more advanced in HIV-HCV patients (single nodule: 43% vs. 75%, P=0.07; mean diameter of main nodule: 24 vs. 16 mm, P=0.006; portal obstruction: 3 vs. 0). Curative treatment was performed in four HIV-HCV patients versus 11 HCV patients (P=0.017). During follow-up, 10 HIV-HCV patients died versus only one HCV patient (P=0.0005). CONCLUSIONS: This result suggests more aggressiveness for tumors in HIV infected patients and, if confirmed, could result in shortening the length between ultrasonographic examinations

L’index FIB-4 pour faire le diagnostic de fibrose hépatique avancée au cours de la stéatose hépatique = FIB-4 index to rule-out advanced liver fibrosis in NAFLD patients

The FIB-4 index is a biomarker of advanced hepatic fibrosis in a context of fatty liver disease. The calculation of the FIB-4 index requires of age, serum ALT and AST transaminase levels and platelet count. A FIB-4 index < 1.45 in a context of fatty liver disease excludes clinically significant hepatic fibrosis. Additional explorations are mandatory to excluded hepatic fibrosis for a a FIB-4 index > 1.45 in a context of fatty liver disease. A complete hepatological workup is mafatory for a FIB-4 index > 3.25 in a context of fatty liver disease

Trends in HCV treatment uptake, efficacy and impact on liver fibrosis in the Swiss HIV Cohort Study.

Hepatitis C virus (HCV) therapies with interferon-free second-generation direct-acting antivirals (DAAs) are highly effective and well tolerated. They have the potential to increase treatment eligibility and efficacy in HIV-infected patients. We assessed the impact of DAAs on treatment uptake and efficacy, as well as its impact on the burden of liver disease in the Swiss HIV Cohort Study (SHCS). We describe clinical and virological characteristics of patients treated with second-generation DAAs. We compared treatment incidence, sustained virological response (SVR)12 and liver fibrosis stages between three time periods: period 1, 01/2009-08/2011 (prior to the availability of DAAs); period 2, 09/2011-03/2014 (first generation DAAs); period 3, 04/2014-12/2015 (second generation DAAs). At the beginning of the third period, 876 SHCS participants had a chronic HCV infection of whom 180 (20%) started treatment with a second-generation DAA. Three-quarters of them had advanced liver fibrosis (Metavir ≥ F3) of whom 80% were cirrhotics. SVR12 was achieved in 173/180 (96%) patients, three patients died and four experienced a virological failure. Over the three time periods, treatment uptake (4.5/100 py, 5.7/100 py, 22.4/100 py) and efficacy (54%, 70%, 96% SVR12) continuously increased. The proportion of cirrhotic patients with replicating HCV infection in the SHCS declined from 25% at the beginning to 12% at the end of the last period. After the introduction of second-generation DAAs, we observed an increase in treatment uptake and efficacy which resulted in a significant reduction in the number of cirrhotic patients with a replicating HCV infection in the SHCS