Pretreatment Donors after Circulatory Death with Simvastatin Alleviates Liver Ischemia Reperfusion Injury through a KLF2-Dependent Mechanism in Rat

Objective. Severe hepatic ischemia reperfusion injury (IRI) can result in poor short- and long-term graft outcome after transplantation. The way to improve the viability of livers from donors after circulatory death (DCD) is currently limited. The aim of the present study was to explore the protective effect of simvastatin on DCD livers and investigate the underlying mechanism. Methods. 24 male rats randomly received simvastatin or its vehicle. 30 min later, rat livers were exposed to warm ischemia in situ for 30 min. Livers were removed and cold-stored in UW solution for 24 h, subsequently reperfused for 60 min with an isolated perfused rat liver system. Liver injury was evaluated during and after warm reperfusion. Results. Pretreatment of DCD donors with simvastatin significantly decreased IRI liver enzyme release, increased bile output and ATP, and ameliorated hepatic pathological changes. Simvastatin maintained the expression of KLF2 and its protective target genes (eNOS, TM, and HO-1), reduced oxidative stress, inhibited innate immune responses and inflammation, and increased the expression of Bcl-2/Bax to suppress hepatocyte apoptosis compared to DCD control group. Conclusion. Pretreatment of DCD donors with simvastatin improves DCD livers’ functional recovery probably through a KLF2-dependent mechanism. These data suggest that simvastatin may provide a potential benefit for clinical DCD liver transplantation

Bottleneck Prediction and Resilience Improvement for Manufacturing Systems

Improving production system performance is a constant need and a priority for manufacturers. Planning effective operations to maintain high throughput and resilience during production is not a trivial task. Manufacturers are looking for systematic, reliable, and efficient tools to reach their production goals, in the face of increasing production complexity, unplanned disruptions, and uncertain customer demands. This proposed dissertation aims at developing relevant tools to support real-time throughput and resilience improvement decision-making in complex manufacturing systems. First, a methodology is proposed for detecting dynamic throughput bottlenecks for manufacturing systems with non-serial layout conditions. Existing data-driven bottleneck detection tools are well studied for serial lines. In this study, a systematic framework is proposed to extend a well-known bottleneck detection method to complex manufacturing systems, with loop and parallel structures. The spatial distribution of station blockage time and starvation time is selected as the main indicator for identifying bottlenecks, based on their reflection of production system dynamics. Second, the dissertation investigates the predictive modeling for forecasting throughput bottlenecks. The concepts of factory physics by Professor Wallace Hopp are applied to identify dominant features that collaboratively affect the bottleneck locations in a system. A machine learning algorithm (Long Short-Term Memory, LSTM) is adopted to effectively capture time series dynamics and handle high dimensional inputs. Third, the dissertation proposes a framework for resilience dynamics modeling and control. Disruptions near bottleneck locations can have significant impact on system throughput. A resilient manufacturing system is capable of managing and maintaining throughput in an environment with stochastic disruptions. This research explores how to incorporate the bottleneck detection model with the proposed resilience dynamics model for improving real-time production operations (order dispatching) to achieve higher resilience and throughput during production. The proposed methodologies are developed and validated alongside the support of industrial experts. For the bottleneck detection and prediction models, the effectiveness of the approach is evaluated upon daily industrial data in a major automotive OEM with a span over 1 year. The bottleneck detection tools implemented have made tangible impact at the plant. The resilience dynamics modeling and control is formulated with close cooperation with industrial partners to make sure that the solutions are relevant and applicable to their production scenarios. The simulation platform and the results are closely evaluated by industrial researchers and practitioners. Overall, the dissertation proposed methodologies with both scientific and engineering contributions. The tools developed in this dissertation, if deployed correctly, can provide manufacturers greater capabilities in improving its throughput and overall equipment effectiveness (OEE).PHDMechanical EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/174268/1/xingjian_1.pd

Knitting 4D garments with elasticity controlled for body motion

In this paper, we present a new computational pipeline for designing and fabricating 4D garments as knitwear that considers comfort during body movement. This is achieved by careful control of elasticity distribution to reduce uncomfortable pressure and unwanted sliding caused by body motion. We exploit the ability to knit patterns in different elastic levels by single-jersey jacquard (SJJ) with two yarns. We design the distribution of elasticity for a garment by physics-based computation, the optimized elasticity on the garment is then converted into instructions for a digital knitting machine by two algorithms proposed in this paper. Specifically, a graph-based algorithm is proposed to generate knittable stitch meshes that can accurately capture the 3D shape of a garment, and a tiling algorithm is employed to assign SJJ patterns on the stitch mesh to realize the designed distribution of elasticity. The effectiveness of our approach is verified on simulation results and on specimens physically fabricated by knitting machines. Accepted Author ManuscriptMaterials and ManufacturingMechatronic Desig

Sonographic and Clinical Features of Papillary Thyroid Microcarcinoma Less than or Equal to Five Millimeters: A Retrospective Study

<div><p>Objective</p><p>To retrospectively compare the sonographic and clinical features of papillary thyroid microcarcinoma (PTMC) ≤5 mm and PTMC >5 mm to improve the diagnostic value of ultrasonography.</p><p>Methods</p><p>A total of 367 cases of PTMC between January 2013 and December 2014 was included in this study. The patients were classified into group A (≤5 mm, n = 181) or group B (>5 mm, n = 186), and the sonographic and clinical features were reviewed and compared between the two groups.</p><p>Results</p><p>There was no significant difference in the shape, ratio of length/width, boundary, peripheral halo ring, echogenicity, cystic change and accompanying Hashimoto's thyroiditis between these two groups. However, the calcification (61.3% vs. 72.6%) and hypervascularity (13.8% vs. 24.7%) were more frequent in group B (p = 0.026 and 0.008, respectively). The patients were younger, and more patients were aged less than 45 years (41.4% vs. 57.0%) in group B. Capsular invasion (7.2% vs. 34.4%), multifocality (21.5% vs. 48.9%), bilaterality (17.1% vs. 39.8%), central lymph node metastasis (13.8% vs. 38.2%) and lateral lymph node metastasis (1.1% vs. 5.4%) were more frequent in group B. No clinical or sonographic feature was related to cervical lymph node metastasis in group A, while less than 45 years in age (p = 0.010), male gender (p = 0.040), capsular invasion (p<0.001), multifocality (p = 0.016) and calcification (p = 0.042) were related to cervical lymph node metastasis in group B.</p><p>Conclusions</p><p>The sonographic features of PTMC ≤5 mm were similar to those of PTMC >5 mm, including an irregular shape, a length/width ratio of ≥1, an unclear boundary, no peripheral halo ring, hypoechogenicity, no cystic change, calcification, no hypervascularity and no accompanying Hashimoto's thyroiditis. The clinical features of PTMC ≤5 mm were less aggressive than those of PTMC >5 mm.</p></div

Comparison of sonographic features between the two groups.

<p>Comparison of sonographic features between the two groups.</p

Sonographic features related to lymph node metastasis in group A.

<p>Sonographic features related to lymph node metastasis in group A.</p

Comparison of clinical features between the two groups.

<p>Comparison of clinical features between the two groups.</p

A 38-year-old female patient with papillary thyroid microcarcinoma less than or equal to 5 mm.

<p>(a) The longitudinal gray scale sonogram shows an irregular shape, a length/width ratio of ≥1, an unclear boundary, no peripheral halo ring, hypoechogenicity, no cystic change and no accompanying Hashimoto's thyroiditis. (b) The longitudinal color sonogram shows no hypervascularity. (c) The transverse gray scale sonogram shows an irregular shape, a length/width ratio of ≥1, an unclear boundary, no peripheral halo ring, hypoechogenicity, no cystic change and no accompanying Hashimoto's thyroiditis. (d) The transverse color sonogram shows no hypervascularity.</p