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Influence of surface conditions and embedment length on the bond-slip response of GFRP rebars in concrete
No full textReinforcing concrete members with fibre-reinforced polymer (FRP) rebars, as an alternative to common corrosion-prone steel rebars, is steadily increasing, leveraging on their potential to ensure longer structural service lives. Another boost will come from the second generation of Eurocode 2, which for the first time includes supplementary guidance for the design of new structures with non-prestressed glass and carbon fibre reinforcement. Several technological developments are ongoing to optimize the performance of FRP rebars, namely regarding their surface and bond-slip response. This topic is investigated herein via an experimental program focusing on two complementary aspects: (i) the influence of various surface conditions on the bond stress-slip behaviour of glass FRP (GFRP) rebars with thermoset and thermoplastic polymers; machine-coated and helically-wrapped sand-coated surfaces are included, as well as newer approaches to surface treatment such as peel-ply and peel-ply/grid; (ii) the influence of different embedment lengths, namely 10×, 20×, and 30× the rebar diameter, on the pull-out response of GFRP rebars with a yet-distinct surface treatment known as calendering; this paper briefly shows and discusses the evolution of strains along the three embedment lengths up until pull-out failure, as obtained from distributed optical fibre sensors, which is another novelty
Alcohol embolization versus non-invasive treatment for pain relief in peripheral venous malformations: a comparative study
No full textBackground: Pain is one of the most important symptoms affecting quality of life in patients with venous malformations. Alcohol embolization is a common approach among other treatment modalities. However, the benefits and complications of this therapy require rigorous evaluation in the face of emerging alternative treatments. The aim of this study was to evaluate the efficacy of alcohol embolization in pain management compared with non-invasive treatment, and to explore associated complications. Methods: We performed a retrospective, comparative study at the Vascular Malformation Center, University Hospital of Bern, from 2008 to 2022. Consecutive patients with peripheral venous malformations were included, one group underwent alcohol embolization and the other group received non-invasive treatment including counseling for compression stockings, physical therapy and anticoagulation. Decision to treat was made jointly by the clinician and the patient, after discussing the potential harms and benefits. Pain levels were measured using the 0–10 Numerical Rating Scale on every scheduled visit. Inverse probability of treatment weights were used to adjust for confounders such as severity of malformation indicated by number of tissues affected, localization, presence of hypertrophic tissue, history of thrombophlebitis, age, and level of pain at the initial visit. The primary outcome was change in maximal pain level, and secondary outcomes included changes in mean and minimal pain levels within 1 year of follow-up. Results: A total of 227 patients were included in the analysis, 86 in the intervention group and 141 in the control group. Over the course of one year, both the control and alcohol embolization groups experienced reductions in pain. The control group showed a reduction in maximal pain from 4.42 by 0.95 points, with an additional non-significant reduction of 0.99 points in the alcohol embolization group [estimate: −0.0027 per day, 95% confidence interval (CI): −0.0061, 0.0007, P=0.12]. However, alcohol embolization led to a more pronounced and significant reduction in mean and minimal pain, with additional reductions of 1.06 (−0.0029 per day, 95% CI: −0.0055, −0.0003, P=0.02) and 0.69 points per year (−0.0019 per day, 95% CI: −0.0035, −0.0004, P=0.01), respectively. Seven minor and five major complications occurred in the alcohol embolization group. Conclusions: Non-invasive treatment helps patients with venous malformations to manage maximal pain effectively. Alcohol embolization results in a faster and more pronounced reduction in mean and minimal pain levels, but we found no statistical evidence of an advantage of alcohol embolization for reducing maximal pain. Treatment efficacy did not appear to be influenced by gender, age, or previous treatment history. To adequately assess the efficacy of new therapies, future trials should include both disease-specific, patient-reported outcome measures and a control group
Influence des configurations familiales sur le bilinguisme chez les enfants sino belges francophones
No full textCette étude explore l’impact des configurations familiales sur les compétences rédactionnelles bilingues (français et chinois) des enfants issus de familles immigrées chinoises en Belgique francophone. Bien que les recherches aient démontré que les configurations familiales influencent les compétences lexicales et syntaxiques des enfants (De Houwer, 2019), la majorité des études se concentrent sur des langues indo-européennes (Kapantzoglou et al., 2021), laissant peu de place aux communautés asiatiques, notamment chinoises, où les systèmes d’écriture diffèrent radicalement (Sun et Kwon, 2020). Contrairement à la plupart des études qualitatives précédentes, cet article adopte une approche quantitative combinant questionnaires et analyse automatique du langage, pour mesurer précisément l’étendue de cette influence. Trente participants âgés de 10 à 16 ans ont rédigé un texte en français et un en chinois. Les caractéristiques familiales (type de famille, nombre d’enfants, ordre de naissance, interactions avec les grands-parents) ont été recueillies par questionnaire. Les textes ont été analysés avec FABRA (Wilkens et al., 2022) pour le français et CRIE (Sung et al., 2016) pour le chinois. Les données ont ensuite été soumises à des tests statistiques, incluant des corrélations et des tests de significativité. Les résultats révèlent que les enfants issus de familles mixtes développent une meilleure maîtrise du français, avec une sophistication lexicale et une complexité syntaxique accrues, confirmant l’influence de l’exposition à la langue majoritaire (De Houwer, 2019). À l’inverse, les enfants de familles non mixtes présentent une plus grande richesse dans leurs productions en chinois, ce qui rejoint les travaux de Sun et Kwon (2020) sur la continuité linguistique. Le temps passé avec les grands-parents chinois est associé à une diminution de la maîtrise du français écrit, probablement en raison d’une exposition réduite à cette langue. Ces dynamiques mettent en évidence le rôle des pratiques familiales dans le développement du bilinguisme des enfants immigrants
Challenges in retrohepatic inferior vena cava reconstruction: The neocava technique
No full textThe development of innovative surgical techniques has been a constant and fundamental aspect in liver transplantation (LT) to address chronic organ shortage. Domino liver transplantation (DLT), initially performed by Furtado et al. in Lisbon in 1995, is an innovative technique in which a liver from a patient with a metabolic disorder is transplanted into a recipient with end-stage liver disease [1]. Simultaneously, advancements in liver tumor resectability have progressed to reduce the need for allograft LT, thereby circumventing issues related to organ shortage and complications of immunosuppression. Ex-situ liver resection and autotransplantation (ELRA), an extreme liver surgery technique embodies this principle. First performed in 1988 in Hannover by Pichlmayr et al. [2], ELRA involves performing tumor excision on the back-table following a total hepatectomy, after which the liver is reimplanted. This technique enables the achievement of an R0 surgical margin, which is often unattainable with conventional approaches. The primary indications for ELRA include tumors invading the hepatic hilum or retrohepatic inferior vena cava (IVC), where resection of these major vessels is required. These techniques are now well-established and indicated in selected patients, offering advantages such as shorter waiting listing time, reduced mortality rates, and complete liver tumor clearance. Historically, in the classic LT technique, liver outflow is restored through recipient’s IVC replacement under cross clamping, a technique that often results in hemodynamic instability due to insufficient cardiac venous return, which can be circumvented by the establishment of a temporary veno-venous bypass [3]. Nowadays, the piggyback technique has largely replaced the classical approach, as it can be performed without necessity of IVC cross clamping, thereby avoiding the preload drop [4]. Two variations of this technique are widely used: (1) in standard piggyback (SPB), graft supra-hepatic venocaval cuff is anastomosed end-to-side to the recipient’s enlarged hepatic veins cuff (corresponding to the initial definition of piggyback technique) [4]; (2) in the modified piggyback (MPB), the liver outflow is ensured via a side-to-side anastomosis between the donor and recipient IVCs under lateral clamping (also known as side-to-side cavo-cavoplasty) [5]. This outflow restoration technique is now standardized for nearly 30 years in our institution [6]. A recent meta-analysis showed that both SPB and MPB offer comparable postoperative outcomes and are associated with shorter operative time, as well as reduced need for red blood cells and fresh frozen plasma transfusions compared to the classical technique [7]. In DLT, liver procurement spares the domino donor’s retrohepatic IVC (living donor). In ELRA for retrohepatic IVC invasion (IVC-ELRA), the IVC is resected on the back-table after total hepatectomy due to tumor invasion. During this procedure, the native IVC is reconstructed with tubulized autologous peritoneum, biobank homologous venous grafts, or Gore-Tex before liver reimplantation. In all cases, the stump of the common trunk and right hepatic vein is short, making SPB anastomosis technically challenging, potentially leading to hepatic vein outflow obstruction (HVOO), therefore associated with a risk of liver congestion, hemorrhage, and ascites. All these conditions lead to graft failure and even fatal for the patient. In this context, various IVC suprahepatic tripod reconstructions have been described to facilitate SPB anastomosis [[8], [9], [10]]. The aim of this work is to provide a detailed description of a simplified retrohepatic IVC surgical reconstruction technique. This allows a hepatic outflow restoration with standard side-to-side cavo-cavoplasty (MPB) following the IVC-ELRA and DLT. This technique was based on our center extensive experience about tubulized IVC reconstruction using cryopreserved venous allograft or autologous peritoneum in multivisceral resections [11,12]. According to this experience, such tubulized IVC reconstruction is considered as a well-settled and standardized procedure. Both patients were aware of the different possibilities for IVC reconstruction and consented for the surgery. In case No. 1 (DLT procedure), LT indication was decompensated cirrhosis (primary sclerosing cholangitis) in a 68-year-old male, complicated by encephalopathy, refractory pruritus and ascites. The graft was issued from a 53-year-old female affected by familial amyloidosis complicated by end-stage kidney failure. There were no other organs affected by amyloidosis nor portal hypertension. Therefore, DLT indication was retained. Cold ischemia time (CIT) and warm ischemia time (WIT) were 236 and 36 minutes, respectively, with 700 mL total blood loss (no transfusion required). WIT consisted in 3 minutes of donor’s functional WIT and 33 minutes of receiver’s WIT (side-to-side cavo-cavoplasty and portal vein anastomosis). In case No. 2, an 84-year-old female in excellent general condition [Eastern Cooperative Oncology Group (ECOG) score 0] was diagnosed with primary IVC leiomyosarcoma located at hepato-caval confluence. The tumor extended intrahepatically posteriorly up to the confluence of the three hepatic veins and exhibited a 5-cm extension into the right atrium. This thrombus was causing rapidly progressing dyspnea due to impaired cardiac venous return. Without surgical intervention, this thrombus would have led to terminal cardiac failure and pulmonary embolism in a short time frame. Surgical treatment was discussed with the patient and within a multidisciplinary meeting, who unanimously approved the procedure: IVC-ELRA indication under sterno-laparotomy was decided. We performed atriotomy with thrombus extraction and partial right atrium resection under extra-corporeal circulation (230 minutes) [13]. CIT and WIT were 220 and 26 minutes, respectively. The estimated intraoperative blood loss was 3 L, essentially related to cardiac surgery. We transfused 3 units of packed red blood cells. WIT consisted in 6 minutes of donor’s functional WIT and 20 minutes of receiver’s WIT (side-to-side cavo-cavoplasty and portal vein anastomosis) [13]. In both cases, homologous venous iliaco-caval graft (either cadaveric or cryopreserved) was used for retrohepatic IVC reconstruction. The iliac limbs of the graft were opened medially and tighted together with running sutures along the anterior and posterior walls to create a large tubular vein, which served as the neocava. On the back-table, the cavo-hepatic confluence was reconstructed using the distal iliac segments of the tube, chosen for its wider caliber, to form the new cavo-hepatic confluence. The common trunk of the hepatic veins was anastomosed to the left lateral aspect of the neocava through a transverse incision, while the right hepatic vein was attached to the right lateral side of the neocava via a longitudinal incision. This configuration was designed to optimize hepatic venous outflow. The superior and inferior ends of the neocava were then closed with a continuous Prolene 6/0 suture (Fig. 1). To ensure vascular integrity, the neocaval vein’s blood-tightness was tested on the back-table. Additionally, a 5-cm incision was made slightly lateral to the ilio-iliac suture on the posterior wall. Fig 1 Download: Download high-res image (2MB) Download: Download full-size image Fig. 1. Liver outflow reconstruction. A: Right hepatic vein anastomosis to neocava in an end-to-side fashion with longitudinal incision on right neocava lateral face. B: Cranial inner view within neocava: right hepatic vein anastomosis *, common trunk anastomosis **. C: A 5 cm-long longitudinal incision on posterior wall of neocava to prepare MPB anastomosis. D: Post-implantation view: MPB anastomosis. MPB: modified piggyback. In case No. 1, postoperative course was uneventful, and a systematic CT scan was performed on postoperative day 7 to assess cavo-caval anastomosis patency (Fig. 2). Patient was discharged 12 days after LT with normal liver function. Fig 2 Download: Download high-res image (506KB) Download: Download full-size image Fig. 2. Computed tomography scan at postoperative day 7. A: Side-to-side cavo-cavoplasty patency. B: Patency of the three hepatic veins. In case No. 2, postoperative course was marked by an early-stage biliary leak, requiring surgical exploration. Further postoperative course was uneventful allowing hospital discharge after 15 days. Nevertheless, patient opted for a transition through rehabilitation before returning home. An additional 17 days were required to secure a spot at the rehabilitation facility. Finally, patient was discharged on postoperative day 32 and was able to go back home 47 days after surgery. Both patients are in good condition 18 months after surgery, with a patent anastomosis, a normal liver function and no HVOO-related complications. By providing a new method to address challenges of retrohepatic IVC reconstruction, we aim to improve graft and patient outcomes by allowing standardized MPB anastomosis. Compared to classical technique, it offers the possibility to perform outflow reconstruction under partial lateral IVC clamping, preserving sufficient preload and thereby avoiding hemodynamic instability and the necessity of a veno-venous bypass. Compared to SPB anastomosis, the neocava technique offers the advantage to easily perform an MPB anastomosis in a standardized way, allowing a short WIT and reducing the risk of HVOO related to the short hepatic vein cuffs. Hepato-caval confluence reconstruction is challenging in both DLT and IVC-ELRA, particularly to perform SPB due to the short hepatic vein cuffs, which increases the risk of HVOO, or classical implantation technique, which increases the risk of unstable patient during surgery. We present a novel approach that involves creating a neocava with a simplified cavo-hepatic confluence reconstruction at a lower cost, without the need for IVC cross-clamping. In our experience, this straightforward technique allows for an MPB technique to restore liver outflow, with favorable early and long-term outcomes, avoiding outflow complications. This method may serve as a valuable tool to expand the range of outflow reconstruction options in these complex and rare cases
Hitting the Right Note: The Impact of Lexical Complexity on Initial Coin Offering Success
No full textThis paper builds on credible signaling theory and proposes a novel approach to financial textual analysis by introducing lexical complexity (LC) as an informative signal of future venture performance. LC is measured by the sophistication, density, and diversity of vocabulary in a text and distinguishes itself from the widely used construct of readability. Analyzing 1,202 ICO white papers from 2015 to 2021, we find that higher LC positively influences the amount raised during ICOs, above and beyond the effect of white paper readability. This effect is amplified for more readable white papers. We also investigate the underlying mechanisms behind these results, suggesting that LC enhances perceptions of innovation and quality, attracts greater attention from institutional investors, and reduces information asymmetry. Our findings contribute to the entrepreneurial finance literature by highlighting how managers’ linguistic choices, particularly the use of LC, can significantly improve disclosure quality and influence investor behavior
Quantitative Measurement of Tau Burden in a Dual-Time-Window Dynamic PET Imaging Protocol with [<sup>18</sup>F]MK6240
No full textThis study aimed to test and validate a dual-time-window (DTW) protocol for 6-(fluoro-18F)-3-(1H-pyrrolo[2,3-c]pyridin-1-yl)isoquinolin-5-amine ([18F]MK6240) dynamic PET imaging in experimental datasets acquired in human subjects. Methods: DTW protocols were tested and validated in datasets previously collected in 25 participants: 13 were cognitively normal, 10 had mild cognitive impairment, and 2 had Alzheimer disease. Participants underwent full 120-min [18F]MK6240 dynamic PET scans as well as structural MRI. Intermediary 3-dimensional volumes were removed from the acquired dynamic PET images to emulate DTW acquisitions consisting of an early phase and a late phase. Five break durations (30, 40, 50, 60, and 70 min) were investigated to determine the optimal break for 2 study durations (120 and 110 min). Regional brain time-activity curves were extracted using atlases available in the Montreal Neurologic Institute template space and using the FreeSurfer parcellation. Interpolation strategies were tested to recover the missing time points. Distribution volume ratio (DVR) estimates obtained from the DTW time-activity curves were compared with those obtained from the full time-activity curves as reference. Parametric maps were generated for the selected protocol and evaluated. Results: The correlation and agreement between DVR values obtained from the DTW method and the full time-activity curves were overall very good. The DTW protocol with a 60-min break using a biexponential model fit as the interpolation method provided the best compromise between practicality and quantitative accuracy. The mean differences between this DTW and the full acquisition, averaged across brain regions and all subjects, were less than 1% with a corresponding SD of less than 4%, and DVR estimates were not statistically different from those obtained from the full acquisition (P > 0.05). DVR parametric images were visually and quantitatively consistent with those obtained from the full acquisition. Conclusion: This study presents strong support for the use of a DTW protocol with [18F]MK6240. Such a protocol would be well suited to allow for both quantification of tau and derivation of an index of cerebral perfusion while reducing patient discomfort and increasing scanning efficiency in comparison to a full dynamic acquisition. Keywords: Alzheimer disease; PET; [18F]MK6240; dual-time-window imaging; tau imaging
Everolimus Personalized Therapy: Second Consensus Report by the International Association of Therapeutic Drug Monitoring and Clinical Toxicology
No full textThe Immunosuppressive Drugs Scientific Committee of the International Association of Therapeutic Drug Monitoring and Clinical Toxicology established the second consensus report to guide therapeutic drug monitoring (TDM) of everolimus (EVR) and its optimal use in clinical practice 7 years after the first version was published in 2016. This version provides information focused on new developments that have arisen in the last 7 years. For the general aspects of the pharmacology and TDM of EVR that have retained their relevance, readers can refer to the 2016 document. This edition includes new evidence from the literature, focusing on the topics updated during the last 7 years, including indirect pharmacological effects of EVR on the mammalian target of rapamycin complex 2 with the major mechanism of direct inhibition of the mammalian target of rapamycin complex 1. In addition, various concepts and technical options to monitor EVR concentrations, improve analytical performance, and increase the number of options available for immunochemical analytical methods have been included. Only limited new pharmacogenetic information regarding EVR has emerged; however, pharmacometrics and model-informed precision dosing have been constructed using physiological parameters as covariates, including pharmacogenetic information. In clinical settings, EVR is combined with a decreased dose of calcineurin inhibitors, such as tacrolimus and cyclosporine, instead of mycophenolic acid. The literature and recommendations for specific organ transplantations, such as that of the kidneys, liver, heart, and lungs, as well as for oncology and pediatrics have been updated. EVR TDM for pancreatic and islet transplantation has been added to this edition. The pharmacodynamic monitoring of EVR in organ transplantation has also been updated. These updates and additions, along with the previous version of this consensus document, will be helpful to clinicians and researchers treating patients receiving EVR
La sarcopénie, présente chez les patients cirrhotiques avec une dénutrition modérée à sévère est associée à une densité accrue du tissu adipeux.
No full textIntroduction : La sarcopénie et la dénutrition sont des complications fréquentes chez les patients atteints de cirrhose en attente de transplantation hépatique. Récemment, des études ont mis en évidence le rôle majeur de la densité du tissu adipeux (TA) en tant que facteur pronostique de mortalité et de morbidité, en particulier dans les maladies chroniques et notamment le cancer. Cependant, la densité du TA chez les patients cirrhotiques en attente de greffe demeure largement sous-étudiée. Méthodes : 26 patients cirrhotiques ont été recrutés prospectivement dans le cadre de leur bilan pré-greffe. La dénutrition a été évaluée selon les critères du global leadership initiative on malnutrition (GLIM), et sa sévérité déterminée en fonction de la perte de poids et de la réduction de la masse musculaire. La sarcopénie a été définie selon les recommandations du consensus européen (EWGSOP), incluant une diminution de masse musculaire et une baisse de force musculaire, évaluée par le test de préhension. La densité musculaire ainsi que celle des tissus adipeux viscéral (TAV) et sous-cutané (TASC) ont été analysées au niveau de la L3 par CT-scan. Résultats : Les patients cirrhotiques en attente de transplantation hépatique sont majoritairement des hommes (70 %) avec un IMC moyen de 26 kg/m² (17 ─ 40 kg/m²). Le score MELD moyen est de 16, indiquant une cirrhose avancée. Six patients (23 %) ne présentent pas de dénutrition, tandis que 16 patients (62 %) présentent une dénutrition modérée et 4 patients (15 %) une dénutrition sévère. Une faible force musculaire est observée chez 8 patients (30 %), et une faible masse musculaire chez 11 patients (41 %). Quatre patients (15 %) répondent aux critères de sarcopénie, tous ceux-ci sont dénutris. La densité moyenne du TASC est de -78 HU (-97 ─ -52 HU) et la densité moyenne du TAV est de -76 HU (-88 ¬ ─ -65 HU). Enfin, les patients sarcopéniques présentent une densité significativement plus élevée du TAV et du TASC par rapport aux patients non sarcopéniques (-62 vs -86 HU, p = 0,0145 ; -69 vs -78 HU, p = 0,0145) (Figure). Conclusion : Chez les patients cirrhotiques en attente de greffe hépatique, la sarcopénie observée chez les patients présentant une dénutrition modérée à sévère est associée à une densité accrue du tissu adipeux. Ces résultats suggèrent une limitation de l'expansion du TA ou un état inflammatoire, potentiellement délétères pour l'organisme, soulignant la nécessité d'études physiopathologiques
