Reflected Shock Bifurcation in a Square Channel

We examine the bifurcation of a reflected shock in a three-dimensional, square channel through numerical simulations using a distributed memory parallel adaptive mesh refinement, Navier-Stokes solver with multicomponent equation of state and microscopic transport. The three-dimensional, rather than axisymmetric, geometry introduces considerable complexity into the flow structures, particularly in the vicinity of the corners. Spanwise cross-sections show the boundary layer growth is significantly reduced in the corner regions, where the shape of the turbulent jet and recirculation regions are modified. This appears to be consistent with existing experimental studies which report the boundary layer in the corner region is deformed and the propagation velocity is reduced. A pair of triple points and a diagonally-oriented Mach reflection with shear layers directed towards the corner apex are also observed in the spanwise view

How mobile technologies support business models: Case study-based empirical analysis

[Otros] Les technologies mobiles ont poussé la connectivité des systèmes informatiques à la limite, permettant aux personnes et aux objets de se connecter les uns aux autres à tout moment. La quantité d'informations dont disposent les entreprises a augmenté de façon exponentielle, en grande partie grâce à la géolocalisation et à la vaste gamme de capteurs intégrés dans les appareils mobiles. Ces informations peuvent être utilisées pour améliorer les activités et les processus métier, mais également pour créer de nouveaux modèles d'affaires. En nous concentrant sur les modèles d'affaires, nous analysons les technologies mobiles comme catalyseurs des changements d'activité. Nous examinons les caractéristiques distinctives des technologies mobiles et examinons comment celles¿ci peuvent supporter différentes fonctions de l'entreprise. Une étude basée sur une analyse qualitative comparée d'ensemble floue (fsQCA) de 30 cas, de différents secteurs, a permis d'identifier les facteurs de succès de la technologie mobile pour différentes activités du cœur de métier des firmes. Les résultats montrent que plusieurs combinaisons de technologie mobile procurent un avantage concurrentiel lorsqu'elles correspondent au modèle d'affaire.[EN] Mobile technologies have pushed the connectivity of IT systems to the limit, enabling people and things to connect to one another at all times. The amount of information companies have at their disposal has increased exponentially, thanks largely to geolocation and to the vast array of sensors that have been integrated into mobile devices. This information can be used to enhance business activities and processes, but it can also be used to create new business models. Focusing on business models, we analyze mobile technologies as enablers of activity changes. We consider the differentiating characteristics of mobile technologies and examine how these can support different business functions. A study based on fuzzy-set qualitative comparative analysis (fsQCA) of 30 cases across different industries allows us to identify mobile technology success factors for different core activities. The results show that several combinations of mobile technology initiatives provide a competitive advantage when these initiatives match the business model.Peris-Ortiz, M.; Devece Carañana, CA.; Hikkerova, L. (2020). How mobile technologies support business models: Case study-based empirical analysis. Canadian Journal of Administrative Sciences / Revue Canadienne des Sciences de l Administration. 37(1):95-105. https://doi.org/10.1002/cjas.1550S95105371Al-Debei, M. M., & Avison, D. (2010). Developing a unified framework of the business model concept. 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Information Technology and Management, 9(3), 215-232. doi:10.1007/s10799-008-0040-3Liang, T., Huang, C., Yeh, Y., & Lin, B. (2007). Adoption of mobile technology in business: a fit‐viability model. Industrial Management & Data Systems, 107(8), 1154-1169. doi:10.1108/02635570710822796Martinez-Simarro, D., Devece, C., & Llopis-Albert, C. (2015). How information systems strategy moderates the relationship between business strategy and performance. Journal of Business Research, 68(7), 1592-1594. doi:10.1016/j.jbusres.2015.01.057Mello P.A.(2012).A critical review of applications in QCA and fuzzy‐set analysis and a ‘toolbox' of proven solutions to frequently encountered problems APSA Annual Meeting Paper. Retrieved fromhttps://ssrn.com/abstract=2105539Melville, Kraemer, & Gurbaxani. (2004). Review: Information Technology and Organizational Performance: An Integrative Model of IT Business Value. MIS Quarterly, 28(2), 283. doi:10.2307/25148636Ngai, E. W. T., & Gunasekaran, A. (2007). 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Working Paper University of Arizona Arizona.Ray, G., Barney, J. B., & Muhanna, W. A. (2003). Capabilities, business processes, and competitive advantage: choosing the dependent variable in empirical tests of the resource-based view. Strategic Management Journal, 25(1), 23-37. doi:10.1002/smj.366Richter, C., Kraus, S., & Syrjä, P. (2015). The shareconomy as a precursor for digital entrepreneurship business models. International Journal of Entrepreneurship and Small Business, 25(1), 18. doi:10.1504/ijesb.2015.068773Schneider, M. R., Schulze-Bentrop, C., & Paunescu, M. (2009). Mapping the institutional capital of high-tech firms: A fuzzy-set analysis of capitalist variety and export performance. Journal of International Business Studies, 41(2), 246-266. doi:10.1057/jibs.2009.36Sheng, H., Nah, F. F.-H., & Siau, K. (2005). Strategic implications of mobile technology: A case study using Value-Focused Thinking. 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Validation of the AASLD recommendations for Classification of Oesophageal Varices in Clinical Practice

Background & Aims The American Association for the Study of Liver Diseases recommends the use of a 2‐grade classification system (small and large) to describe the size of oesophageal varices (OV). Data on observer agreement (OA) on this system are currently lacking. We aimed to evaluate this classification and compare it to the widely used 3‐grade classification (grade 1 ‘small’, grade 2 ‘medium’, grade 3 ‘large’) among operators of variable experience. Methods High‐definition video recordings of 100 patients with cirrhosis were prospectively collected using standardised criteria. Nine observers of variable experience performed independent evaluations of the videos in random order. OV were scored using both systems. All assessments were repeated a year later by the same observers to assess intra‐observer agreement. Results Interobserver agreement (all observers) using the 2‐grade and the 3‐grade system was k = 0.71 (95% CI: 0.64‐0.78) and k = 0.73 (95% CI: 0.66‐0.79) respectively. When using the 2‐grade system, intra‐observer agreement between hepatologists (n = 3), luminal gastroenterologists (n = 3) and trainee gastroenterologists (n = 3) was k = 0.89 (95% CI: 0.86‐0.91), k = 0.72 (95% CI: 0.67‐0.77), and k = 0.74 (95% CI: 0.67‐0.8) respectively. With the 3‐grade system; intra‐observer agreement between the same three subgroups were k = 0.9 (95% CI: 0.87‐0.92), k = 0.73 (95% CI: 0.68‐0.78), k = 0.77 (95% CI: 0.71‐0.82) respectively. Conclusions There was no difference in OA between the 2‐grade and 3‐grade classification systems. Hepatologists had significantly higher levels of consistency in grading OV. This may have implications to create alternative training models for residents and fellows in the recognition and grading of OV

Care standards for non-alcoholic fatty liver disease in the United Kingdom 2016: a cross-sectional survey

OBJECTIVE: Guidelines for the assessment of non-alcoholic fatty liver disease (NAFLD) have been published in 2016 by National Institute for Health and Care Excellence and European Associations for the study of the Liver-European Association for the study of Diabetes-European Association for the study of Obesity. Prior to publication of these guidelines, we performed a cross-sectional survey of gastroenterologists and hepatologists regarding NAFLD diagnosis and management. DESIGN: An online survey was circulated to members of British Association for the Study of the Liver and British Society of Gastroenterology between February 2016 and May 2016. RESULTS: 175 gastroenterologists/hepatologists responded, 116 completing the survey, representing 84 UK centres. 22% had local NAFLD guidelines. 45% received >300 referrals per year from primary care for investigation of abnormal liver function tests (LFTs). Clinical assessment tended to be performed in secondary rather than primary care including body mass index (82% vs 26%) and non-invasive liver screen (86% vs 32%) and ultrasound (81% vs 37%). Widely used tools for non-invasive fibrosis risk stratification were aspartate transaminase (AST)/alanine transaminase (ALT) ratio (53%), Fibroscan (50%) and NAFLD fibrosis score (41%). 78% considered liver biopsy in selected cases. 50% recommended 10% weight loss target as first-line treatment. Delivery of lifestyle interventions was mostly handed back to primary care (56%). A minority have direct access to community weight management services (22%). Follow-up was favoured by F3/4 fibrosis (72.9%), and high-risk non-invasive fibrosis tests (51%). Discharge was favoured by simple steatosis at biopsy (30%), and low-risk non-invasive scores (25%). CONCLUSIONS: The survey highlights areas for improvement of service provision for NAFLD assessment including improved recognition of non-alcoholic steatohepatitis in people with type 2 diabetes, streamlining abnormal LFT referral pathways, defining non-invasive liver fibrosis assessment tools, use of liver biopsy, managing metabolic syndrome features and improved access to lifestyle interventions

Prevention and management of idiosyncratic drug-induced liver injury: Systematic review and meta-analysis of randomised clinical trials

Conducting randomised clinical trials (RCTs) in idiosyncratic drug-induced liver injury (DILI) is challenging. This systematic review aims to summarise the design and findings of RCTs in the prevention and management of idiosyncratic DILI. A systematic literature search up to January 31st, 2020 was performed. Recognised scales were used to assess methodological bias and quality of the studies. Quantitative and qualitative analyses were performed. Heterogeneity was assessed with I2 statistic. Overall, 22 RCTs were included: 12 on prevention (n = 2,471 patients) and 10 in management (n = 797) of DILI/non-acetaminophen DILI-related acute liver failure (ALF). Silymarin (eight studies), bicyclol (four), magnesium isoglycyrrhizinate (three), N-acetylcysteine (three), tiopronin (one), L-carnitine (one), and traditional Chinese medicines (two) were tested in the intervention arm, while control arm mostly received standard supportive care or placebo. Main efficacy criteria in the prevention RCTs was DILI incidence or peak of liver enzymes value. In management RCTs, the efficacy parameter was usually 50 % decrease or normalisation of liver enzymes, or survival rate in DILI-related ALF patients. Overall, 15 trials described the randomisation method, eight were double-blind (n = 672) and nine had sample size esti- mation (n = 880). Four RCTs involving 377 patients used an intention-to-treat analysis. Based on the scarce number of trials available, tested agents showed limited efficacy in DILI prevention and management and a favourable safety profile. In conclusion, heterogeneity among studies in DILI case qualification and methodologic quality was evident, and the RCTs performed demonstrated limited efficacy of specific interventions. Interna- tional research networks are needed to establish a framework on RCTs design and therapeutic endpoints.This work was supported by grants of Instituto de Salud Carlos III cofounded by Fondo Europeo de Desarrollo Regional - FEDER (contract numbers: PI18/00901; PI18/01804; PT17/0017/0020; PT 20/00127) and Agencia Espan ̃ola del Medicamento. Plataforma de Investigacio ́n Clínica and CIBERehd are funded by ISCIII. MRD holds a Joan Rodes (JR16/00015)/Accio ́n B clinicos investigadores (B-0002-2019), JSC a Rio Hortega (CM17/00243) and IAA a Sara Borrell (CD20/00083) research contract from ISCIII and Consejería de Salud de Andalucía. This publication is based upon work from COST Action “CA17112 - Pro- spective European Drug-Induced Liver Injury Network” supported by COST (European Cooperation in Science and Technology). www.cost.e

Multicenter experience from the UK and Ireland of use of lumen-apposing metal stent for transluminal drainage of pancreatic fluid collections

Background and study aims: Pancreatic fluid collection (PFC) is a common complication of pancreatitis for which endoscopic ultrasound-guided drainage is first-line treatment. A new single-device, lumen-apposing, covered self-expanding metal stent (LAMS) has been licensed for PFC drainage. We therefore present our multicenter experience with the LAMS for PFC drainage in a multicenter prospective case series to assess success and complication rates. Patients and methods: All adult patients from 11 tertiary centers who had LAMS placement for PFC from July 2015 to July 2016 were included. Data including indications, technical success, clinical success, collection resolution, stent removal, early and late adverse events (AEs), mortality and recurrence at 6 months were collected. Results: 116 patients, median age 52.5 years (range 16 – 80) and 67 % male, were treated with a single LAMS in each case. The indication was walled off necrosis (WON) in 70 and pseudocyst in 46. Median size of the PFC was 11 cm (5 – 21 cm) and the estimated median necrotic volume in WON was 30 % (5 % – 90 %). Stent insertion was technically successful in 115 (99.1 %) and clinically successful in 109 (94 %). Early serious AEs (SAEs): n = 7 sepsis, n = 1 stent blockage with food, n = 1 stent migration requiring laparotomy, n = 1 stent dislodgement and n = 1 bleeding requiring emboliZation. Late AEs: n = 1 buried stent and n = 1 esophageal fistula. Non-procedure-related deaths: n = 3 (2.5 %). Conclusion: This multicenter case series demonstrates that use of the new LAMS is feasible, effective and relatively safe in draining PFC with a technical success rate of 99 % and cumulative SAE rate of 11.2 %

The communication of a secondary care diagnosis of autoimmune hepatitis to primary care practitioners: a population-based study

Background Autoimmune Hepatitis is a chronic liver disease which affects young people and can result in liver failure leading to death or transplantation yet there is a lack of information on the incidence and prevalence of this disease and its natural history in the UK. A means of obtaining this information is via the use of clinical databases formed of electronic primary care records. How reliably the diagnosis is coded in such records is however unknown. The aim of this study therefore was to assess the proportion of consultant hepatologist diagnoses of Autoimmune Hepatitis which were accurately recorded in General Practice computerised records. Methods Our study population were patients with Autoimmune Hepatitis diagnosed by consultant hepatologists in the Queens Medical Centre, Nottingham University Hospitals (UK) between 2004 and 2009. We wrote to the general practitioners of these patients to obtain the percentage of patients who had a valid READ code specific for Autoimmune Hepatitis. Results We examined the electronic records of 51 patients who had biopsy evidence and a possible diagnosis of Autoimmune Hepatitis. Forty two of these patients had a confirmed clinical diagnosis of Autoimmune Hepatitis by a consultant hepatologist: we contacted the General Practitioners of these patients obtaining a response rate of 90.5% (39/42 GPs). 37/39 of these GPs responded with coding information and 89% of these patients (33/37) used Read code J638.00 (Autoimmune Hepatitis) to record a diagnosis. Conclusions The diagnosis of Autoimmune Hepatitis made by a Consultant Hepatologist is accurately communicated to and electronically recorded by primary care in the UK. As a large proportion of cases of Autoimmune Hepatitis are recorded in primary care, this minimises the risk of introducing selection bias and therefore selecting cases using these data will be a valid method of conducting population based studies on Autoimmune Hepatitis