Assessment of COVID-19 intervention strategies in the Nordic countries using genomic epidemiology

We explored how the duration, size and number of virus transmission clusters, defined as country-specific monophyletic groups in a SARS-CoV-2 phylogenetic tree, differed between the Nordic countries of Norway, Sweden, Denmark, Finland and Iceland. Our results suggest that although geographical connectivity, population density and openness influence the spread and the size of SARS-CoV-2 transmission clusters, the differing country-specific intervention strategies had the largest impact. We also found a significant positive association between the size and duration of transmission clusters in the Nordic countries, suggesting that the rapid deployment of contact tracing is a key response measure in reducing virus transmission.

Genome-wide circulating tumor DNA monitoring for bladder cancer treatment management and organ preservation.

e16527 Background: Bladder cancer (BC) is the 9th most commonly diagnosed cancer worldwide and each year responsible for 165,000 deaths. Neoadjuvant combination chemotherapy, followed by radical cystectomy, is used for the management of localized muscle-invasive bladder cancer. One of the critical challenges in this therapeutic regimen is monitoring the tumor load to assess therapeutic efficacy – this is typically performed by assessing pathological downstaging in the cystectomy specimen. A high frequency of patients presents with T0N0 at cystectomy (no indication of residual disease), and consequently, it is vital to investigate organ preservation approaches to identify those patients who may qualify for bladder preservation. For precision oncology, we need to develop quantitative and non-invasive diagnostic methodologies to help the oncologist tailor the treatments to individual patients and monitor them for further clinical decision-making. Methods: Cell-free DNA (cfDNA) mutation detection has shown significant promise in its ability to monitor minimal residual disease and disease relapse by detection of cancer mutations in the peripheral blood. However, the combination of low tumor fraction and limited input material obtained from a typical plasma sample restricts the probability of detecting low metastatic burden in cfDNA through current deep targeted sequencing methods. Results: Here we present results from applying whole-genome sequencing (WGS) of cfDNA. We integrate a genome-wide mutation and copy number monitoring approach coupled with advanced signal processing and Artificial Intelligence (AI) for measuring the tumor load from low-input blood samples (̃1mL of plasma) with ultra-sensitive detection. The increased sensitivity allowed clinical detection of tumor fraction down to 8*10-5 and recurrence detection sensitivity achieving > 65% at the first two months post-surgery. The WGS cfDNA approach is being evaluated on a patient cohort of more than 50 bladder cancer patients with longitudinal plasma sampling during neoadjuvant chemotherapy (response measure), pre-cystectomy (complete response measure), and post-surgery (relapse monitoring). Conclusions: The results indicate the clinical potential of genome-wide mutation integration as an ultra-sensitive, non-invasive diagnostic method for bladder cancer clinical management and bladder organ preservation.

A challenge for healthcare system resilience after an earthquake: The crowdedness of a first-aid hospital by non-urgent patients

After a violent earthquake, the supply of medical services may fall short of the rising demand, leading to overcrowding in hospitals, and, consequently, a collapse in the healthcare system. This paper takes the emergency care system in Taiwan as the research context, where first-aid hospitals are ranked to three levels, advanced, intermediate, and general, and, currently, emphasizes on a general emergency responsibility hospital. Having limited capacity and capability, a general emergency responsibility hospital treats minor and moderate injuries, from which the majority of earthquake-induced casualties suffer. The purpose of this study is to analyze the impact of this group of earthquake-induced non-urgent patients on the performance of a hospital. A patient flow model was built to represent patients’ paths throughout emergency care. Based on the model, discrete event simulation was applied to simulate patients’ trajectories and states of a hospital under four seismic scenarios, where patient visits are 1.4, 1.6, 1.9, and 2.3 times the normal number. A healthcare performance index, Crowdedness Index (CI), is proposed to measure crowdedness on a daily basis, which is defined as the ratio of the average waiting time for treatment to the recommended maximal waiting time. Results of simulations rendered the establishment of empirical equations, describing the relation between the maximum CIs and the patient growth ratios. In the most severe case in this study, the maximum CI exceeds 92 and it takes 10 days to recover from the quality drop. This highlights the problem a general emergency responsibility hospital may encounter if no emergency response measure is implemented. Findings are provided pertaining to the predication of a recovery curve and the alarming level of patient increase, which are supportive information for preparedness planning as well as response measure formulation to improve resilience.

Parametric Influence Study for Laser Cutting on Acrylic

Laser has been employed for producing the complex specimens very efficiently and magnificently. The use of acrylic components is becoming prevalent day by day. Hence it is required to study the various machining techniques for engraving or cutting of acrylic material. The one of the non-traditional machining processes which can be employed efficiently for machining of acrylic is CO2 laser machining. The parametric study of acrylic materials by using CO2 laser machining is discussed in this paper. The scanning speed and the laser power were considered as process parameters and the influence of these parameters is studied on the depth as response measure. The engraving depth is observed to be increasing with increase in power and noted to be decreasing with increase in the scanning speed.