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Sample preparation is a crucial step in single-molecule experiments and involves passivating the microfluidic sample chamber, immobilizing the molecules, and setting experimental buffer conditions. The efficiency of the experiment depends on the quality and speed of sample preparation, which is often performed manually and relies on the experience of the experimenter. This can result in inefficient use of single-molecule samples and time, especially for high-throughput applications. To address this, a pressure-controlled microfluidic system is proposed to automate single-molecule sample preparation. The hardware is based on microfluidic components from ElveFlow and is designed to be cost-effective and adaptable to various microscopy applications. The system includes a reservoir pressure adapter and a reservoir holder designed for additive manufacturing. Two flow chamber designs Ibidi µ-slide and Grace Bio-Labs HybriWell chamber are characterized, and the flow characteristics of the liquid at different volume flow rates VË are simulated using CFD-simulations and compared to experimental and theoretical values. The goal of this work is to establish a straightforward and robust system for single-molecule sample preparation that can increase the efficiency of experiments and reduce the bottleneck of manual sample preparation, particularly for high-throughput applications.
RESUMO
BACKGROUND: Liver transplantation (LT) for severe alcohol-associated hepatitis (AH) remains controversial due to perceived increased recidivism risk after LT because of a lack of protracted abstinence before LT. Data on risk stratification for alcohol relapse after LT are limited. We sought to evaluate the utility of having a mental health program embedded in a transplantation center in risk assessment for alcohol relapse-free patient survival after LT. METHODS: We conducted a prospective analysis of all patients with a diagnosis of severe AH hospitalized at a single transplant center from April 2015 to April 2020. After a comprehensive mental health risk stratification, patients were either waitlisted for LT or declined for waitlisting. The primary endpoint was alcohol relapse-free patient survival rate for those who received LT. The secondary endpoint compared survival rates between patients who received LT and those who did not. The median follow-up was 10 months. RESULTS: Among the 83 patients included in the study, 54 patients were waitlisted for LT (65%, group 1) and 29 were declined (35%, group 2). Patient characteristics and median Model for End-Stage Liver Disease score on presentation were comparable for both cohorts (36 in group 1, 38 in group 2; P = .8). Group 1 had significantly better Stanford Integrated Psychosocial Assessment for Transplantation total scores (median 40 vs 57; P < .01), presence of social support (100% of patients in group 1 vs 76% in group 2; P < .01), and less prevalence of active tobacco smokers (30% in group 1 vs 66% in group 2; P < .01). For those who were not waitlisted, 72.5% experienced rapid deterioration of hepatic function. Among the 54 patients waitlisted, 29 patients received LT (54%), whereas 19 died while on the waiting list (35%). One- and 3-year patient survival after LT were 92.5% and 92.5%, respectively. The overall and sustained alcohol relapse rates after LT were 10.3% and 3.5%, respectively. CONCLUSION: Severe AH is a complex medical and mental health disease and requires an intense risk assessment for recidivism after LT. Our study shows that an integrated transplantation mental health program provides an accurate risk stratification for alcohol relapse after LT, a successful intervention to mitigate recidivism risk, and optimal short-term alcohol relapse-free patient survival. Future studies should focus on enhancing the guidelines for broader application.
