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Reactive transport processes in natural environments often involve many ionic species. The diffusivities of ionic species vary. Since assigning different diffusivities in the advection–diffusion equation leads to charge imbalance, a single diffusivity is usually used for all species. In this work, we apply the Nernst–Planck equation, which resolves unequal diffusivities of the species in an electroneutral manner, to model reactive transport. To demonstrate the advantages of the Nernst–Planck model, we compare the simulation results of transport under reaction-driven flow conditions using the Nernst–Planck model with those of the commonly used single-diffusivity model. All simulations are also compared to well-defined experiments on the scale of centimeters. Our results show that the Nernst–Planck model is valid and particularly relevant for modeling reactive transport processes with an intricate interplay among diffusion, reaction, electromigration, and density-driven convection.

Colectomy is the surgical treatment of choice in patients with severe or complicated ulcerative colitis. Post-colectomy enteritis (PCE) is a rare condition that can develop after proctocolectomy and has been described only in a few individual cases so far. We report the case of a 46-year-old patient with severe and treatment-refractory ulcerative colitis who underwent colectomy. A few days after surgery, the patient presented with acute anemia and hematemesis. Esophagogastroduodenoscopy showed massive inflammation of the duodenum and jejunum. The life-threateningly ill patient was admitted to the intensive-care unit and treated for severe PCE with ciclosporin and corticosteroids. PCE is a distinct inflammation of the small intestine shortly after colectomy. The patient recovered fully and was discharged after prolonged recovery and long-term intensive care therapy.

Background and Aims. Balloon-assisted enteroscopy (BAE) is a well-established tool in the diagnosis and therapy of small bowel diseases. Ink tattooing of the small bowel is used to mark pathologic lesions or the depth of small bowel insertion. The purpose of this study was to determine the safety, the detection rate, and the clinical relevance of ink tattooing during BAE. Methods. We performed a retrospective analysis of all 81 patients who received an ink tattooing during BAE between 2010 and 2015. Results. In all patients, ink tattooing was performed with no complications. 26 patients received a capsule endoscopy after BAE. The tattoo could be detected via capsule endoscopy in 19 of these 26 patients. The tattoo of the previous BAE could be detected via opposite BAE in 2 of 11 patients. In 9 patients, ink tattooing influenced the choice of approach for reenteroscopy. In 7 patients, the tattoo was used for intraoperative localization and in 3 patients for intraoperative localization as well as for reenteroscopy. The intraoperative detection rate of the tattoo was 100%. Conclusion. Ink tattooing of the small intestine is a safe endoscopic procedure to mark the depth of scope insertion or a pathologic lesion during balloon-assisted enteroscopy.

Background: Inflammatory bowel disease (IBD) frequently manifests at a young age, during the peak fertility years. Understanding the risks of negative pregnancy outcomes associated with IBD is crucial for effective pregnancy management and support. Additionally, it is essential to provide patients with the necessary knowledge to make informed choices and foster their confidence in navigating pregnancy while maintaining effective disease management. Although IBD frequently appears during the peak fertility years, knowledge about managing pregnancy in the context of IBD remains limited and often inaccurate among both physicians and patients. Our study aims to assess the complications occurring during pregnancy in patients with IBD, considering the level of disease activity, and to evaluate the standard of care provided to patients with chronic inflammatory conditions through a cohort analysis. Methods: Patients with IBD who had children were included in this single-center mixed-method (retrospective and prospective) study. Clinical data, disease progression, course of pregnancy, and complications were examined in women. Outcomes for children of men with IBD were also analyzed. To supplement the data, a survey addressing various pregnancy-related topics, including all patients from the university outpatient clinic for IBD, was conducted over a period of six months. Results: A total of 410 patients were screened retrospectively between 2010 and 2021. In total, 134 patients who had children were included in the study: 51.4% (n = 69) had Crohn's disease, 44% (n = 59) had ulcerative colitis, and 4.6% (n = 6) had unclassified inflammatory bowel disease. Of the women, 85% (n = 34) were in remission for at least three months before pregnancy, 14.6% (n = 6) experienced an acute flare-up during pregnancy, and 10.3% (n = 4) and 7.7% (n = 3) had active disease at the time of delivery and during breastfeeding, respectively. Patients with IBD who were in remission before pregnancy did not experience a higher risk of pregnancy complications (no cases of pre-eclampsia or placental abruption were reported in this group). However, the rates of gestational diabetes and fever during pregnancy were 10% for those in remission, compared to 25% for those with active disease. Conclusions: Patients with IBD in remission did not present an increased risk of pregnancy complications. However, our survey indicates that those with active disease at conception were more likely to experience complications such as gestational diabetes and fever. These findings underscore the importance of adequate patient education regarding the safety of various IBD medications during pregnancy in order to avoid pregnancy-related complications. [ABSTRACT FROM AUTHOR]

Hydrogen storage in porous geological formations can potentially provide large-scale, seasonal storage of energy. This study investigates the effect of relative permeability hysteresis on the storage processes, particularly addressing the effects on the dynamics of the hydrogen plume, on the two-phase flow regime in the wellbore, and on the storage operations. Numerical simulations of the underground hydrogen storage processes are conducted for scenarios which account for and which ignore hysteresis. The hysteretic constitutive relationships used are based on two independent, experimentally derived datasets from literature. In scenarios that account for hysteresis, the hydrogen plume is less mobile and the hydrogen mass is more dispersed than in scenarios without hysteresis. In addition, hysteresis leads to increased brine upconing and influx into the production borehole. A simple analysis of the two-phase flow regime in the borehole provides an estimate of the required minimum flow rate to ensure annular flow. Though different, both hysteretic constitutive relationships used in this study yield the same trend. All the effects of hysteresis mentioned above are detrimental for hydrogen recovery and tend to be more significant in the first few storage cycles. Operationally, these problems could be addressed by providing for a rest period between injection and production that is long enough to let the hydrogen plume accumulate near the well and potentially by the use of a cushion gas. • Analysed effects of relative permeability hysteresis in underground hydrogen storage. • Hysteresis reduces hydrogen recovery especially in initial storage cycles. • Hysteresis reduces mobility of the hydrogen plume and increases its spread and extent. • Hysteresis increases brine upconing and affects the wellbore flow regime. [ABSTRACT FROM AUTHOR]

Statements: 1 The European Society of Gastrointestinal Endoscopy (ESGE) adheres to the overarching principles of equality of opportunity, fair treatment, nondiscrimination, and diversity of health care professionals. 2 ESGE strongly supports the creation of collaborations within and between national and international endoscopy societies to disseminate the principles of diversity, equality, and inclusion (DEI) in the field of gastrointestinal (GI) endoscopy. 3 ESGE aims to reflect the diversity of its membership in all its scientific and educational activities. 4 ESGE supports the fostering of collaborative work settings that empower all members of the endoscopy team to reach their full potential. 5 ESGE supports international and national endoscopy societies in promoting equitable access to high quality endoscopy training. 6 ESGE recommends the implementation of ergonomic principles in endoscopy units to prevent injuries and to provide adapted workplace conditions for personnel with disabilities and/or special needs. 7 ESGE recommends comprehensive mentorship, that includes diverse backgrounds, and equitable sponsorship for professional development, training, and academic excellence. 8 ESGE recommends that endoscopists actively identify, discuss, and attempt to accommodate reasonable patient preferences and expectations regarding endoscopy procedures. 9 ESGE advocates for educational and awareness campaigns targeting both health care professionals and patients, as well as the adoption of cost-effective health care strategies to address disparities and enhance equity in endoscopy care. 10 ESGE is committed to increasing support for underrepresented scholars and minorities pursuing research in endoscopy. 11 ESGE identifies mentorship and sponsorship as factors that may mitigate the barriers to academic careers for underrepresented endoscopy scholars. 12 ESGE recognizes the need to increase awareness of diversity, equity, and inclusion (DEI) in the field of endoscopy and supports publications on these topics. [ABSTRACT FROM AUTHOR]

Background and aims: Endoscopic submucosal dissection (ESD) has become a standard treatment for early gastric cancer (EGC), often fulfilling guideline criteria (GC) or expanded criteria (EC). When lesions exceed the EC, surgical resection is recommended. However, a subgroup of these patients are not treated surgically. The aim of this study was to investigate the long-term follow-up of patients after ESD for EGC outside the EC (out of indication; OI). Methods: Patients who were included in the prospective German ESD registry were analyzed when ESD was performed for EGC. Patients were stratified in three groups according to histopathological features (GC, EC and OI). The results were evaluated in terms of patient characteristics, procedure characteristics and follow-up data. Results: Over a 48-month period, 195 patients from 14 German centers were included. In total, 71 lesions (36.4%) met the guideline criteria, 70 lesions (35.9%) corresponded to the expanded criteria and 54 lesions (27.7%) turned out to be OI. The R0 resection rate was significantly higher for the GC and EC groups than for the OI group (94.4% vs. 84.3% vs. 55.6%, p < 0.001). Additional surgery was not performed in 72% (39/54) of patients in the OI group. During a mean follow-up of 37 months, overall survival showed no significant difference between the EC and OI groups when endoscopic follow-up was performed without additional surgery (p = 0.064). Conclusions: The results show that a good long-term survival can be achieved after ESD for patients with OI lesions without additional surgery. The treatment decision has to be made on an individual basis, taking the patient's comorbidities and the risk of surgical resection into account. [ABSTRACT FROM AUTHOR]

Background This study evaluated the effect of an artificial intelligence (AI)-based clinical decision support system on the performance and diagnostic confidence of endoscopists in their assessment of Barrett's esophagus (BE). Methods 96 standardized endoscopy videos were assessed by 22 endoscopists with varying degrees of BE experience from 12 centers. Assessment was randomized into two video sets: group A (review first without AI and second with AI) and group B (review first with AI and second without AI). Endoscopists were required to evaluate each video for the presence of Barrett's esophagus-related neoplasia (BERN) and then decide on a spot for a targeted biopsy. After the second assessment, they were allowed to change their clinical decision and confidence level. Results AI had a stand-alone sensitivity, specificity, and accuracy of 92.2%, 68.9%, and 81.3%, respectively. Without AI, BE experts had an overall sensitivity, specificity, and accuracy of 83.3%, 58.1%, and 71.5%, respectively. With AI, BE nonexperts showed a significant improvement in sensitivity and specificity when videos were assessed a second time with AI (sensitivity 69.8% [95%CI 65.2%–74.2%] to 78.0% [95%CI 74.0%–82.0%]; specificity 67.3% [95%CI 62.5%–72.2%] to 72.7% [95%CI 68.2%–77.3%]). In addition, the diagnostic confidence of BE nonexperts improved significantly with AI. Conclusion BE nonexperts benefitted significantly from additional AI. BE experts and nonexperts remained significantly below the stand-alone performance of AI, suggesting that there may be other factors influencing endoscopists' decisions to follow or discard AI advice. [ABSTRACT FROM AUTHOR]