18 research outputs found
Development of a robotic system for automatic organic chemistry synthesis
Automated chemical synthesis carries great promises of safety, efficiency and
reproducibility for both research and industry laboratories. Current approaches
are based on specifically-designed automation systems, which present two major
drawbacks: (i) existing apparatus must be modified to be integrated into the
automation systems; (ii) such systems are not flexible and would require
substantial re-design to handle new reactions or procedures. In this paper, we
propose a system based on a robot arm which, by mimicking the motions of human
chemists, is able to perform complex chemical reactions without any
modifications to the existing setup used by humans. The system is capable of
precise liquid handling, mixing, filtering, and is flexible: new skills and
procedures could be added with minimum effort. We show that the robot is able
to perform a Michael reaction, reaching a yield of 34%, which is comparable to
that obtained by a junior chemist (undergraduate student in Chemistry)
Consensus guidelines for the use and interpretation of angiogenesis assays
The formation of new blood vessels, or angiogenesis, is a complex process that plays important roles in growth and development, tissue and organ regeneration, as well as numerous pathological conditions. Angiogenesis undergoes multiple discrete steps that can be individually evaluated and quantified by a large number of bioassays. These independent assessments hold advantages but also have limitations. This article describes in vivo, ex vivo, and in vitro bioassays that are available for the evaluation of angiogenesis and highlights critical aspects that are relevant for their execution and proper interpretation. As such, this collaborative work is the first edition of consensus guidelines on angiogenesis bioassays to serve for current and future reference
New genetic loci link adipose and insulin biology to body fat distribution.
Body fat distribution is a heritable trait and a well-established predictor of adverse metabolic outcomes, independent of overall adiposity. To increase our understanding of the genetic basis of body fat distribution and its molecular links to cardiometabolic traits, here we conduct genome-wide association meta-analyses of traits related to waist and hip circumferences in up to 224,459 individuals. We identify 49 loci (33 new) associated with waist-to-hip ratio adjusted for body mass index (BMI), and an additional 19 loci newly associated with related waist and hip circumference measures (P < 5 × 10(-8)). In total, 20 of the 49 waist-to-hip ratio adjusted for BMI loci show significant sexual dimorphism, 19 of which display a stronger effect in women. The identified loci were enriched for genes expressed in adipose tissue and for putative regulatory elements in adipocytes. Pathway analyses implicated adipogenesis, angiogenesis, transcriptional regulation and insulin resistance as processes affecting fat distribution, providing insight into potential pathophysiological mechanisms
Benchmark on robotic motion planning algorithms in a drilling task
Sampling-based robotic motion planning algorithms have been the key concept of programming robot motion as they are validated to be probabilistically complete. Thus, numerous research studies have been carried out to continuously improve these algorithms to lower the cost, which includes the time taken to solve the query or the trajectory execution time.
This report covers the benchmark of sampling-based motion planners, such as single-query and multi-query planners, in a static environment to determine whether reusing the roadmap of multi-query planners will reduce the cost of solving multiple queries, as compared to single-query planners where new trees are constructed for every query.
The benchmark requires the use of Open Robotics Automation Virtual Environment (OpenRAVE), which provides an environment to simulate robot motion with their planners, and Open Motion Planning Library (OMPL) which has a variety of motion planners.
The study also includes the integration of OMPL into OpenRAVE since the benchmark is carried out by using planners from not only OpenRAVE, but OMPL as well. Specifically, the benchmark will cover the total time taken to solve the queries with smoothing, total trajectory execution time and robustness of the planners. Also, the programming language used in this project is Python.Bachelor of Engineering (Mechanical Engineering
Automated post-processing of 3D-printed parts: artificial powdering for deep classification and localisation
With the rapid rise in popularity in additive manufacturing, 3D printing technologies are increasingly competitive. However, current post-processing solutions are unable to cope with the varieties of printed parts, where post-production tasks differs for each part based on the desired outcome. Therefore, current post-processing treatments rely heavily on manual labor. Thus, to move towards end-to-end automated post-processing that can cater to individual processes for different parts, a fully automated vision pipeline for classifying and locating parts printed by polymer or metal powder-based processes, such as Selective Laser Sintering (SLS), binder jetting and HP Multi Jet Fusion (MJF) is proposed. The main contributions of this paper are the simulation of powder distribution on the surface of the 3D-printed parts after powder-based printing, and the incorporation of these powdered models in a sim-to-real deep learning pipeline. Our network that was trained on powdered models obtained classification and localisation results comparable to a network trained on real images. Also, the superiority of artificial powder models was shown when compared with using the original, unpowdered CAD models, especially for parts that are significantly different from their CAD models due to powder accumulation
A Bayesian reanalysis of the Standard versus Accelerated Initiation of Renal-Replacement Therapy in Acute Kidney Injury (STARRT-AKI) trial
Background
Timing of initiation of kidney-replacement therapy (KRT) in critically ill patients remains controversial. The Standard versus Accelerated Initiation of Renal-Replacement Therapy in Acute Kidney Injury (STARRT-AKI) trial compared two strategies of KRT initiation (accelerated versus standard) in critically ill patients with acute kidney injury and found neutral results for 90-day all-cause mortality. Probabilistic exploration of the trial endpoints may enable greater understanding of the trial findings. We aimed to perform a reanalysis using a Bayesian framework.
Methods
We performed a secondary analysis of all 2927 patients randomized in multi-national STARRT-AKI trial, performed at 168 centers in 15 countries. The primary endpoint, 90-day all-cause mortality, was evaluated using hierarchical Bayesian logistic regression. A spectrum of priors includes optimistic, neutral, and pessimistic priors, along with priors informed from earlier clinical trials. Secondary endpoints (KRT-free days and hospital-free days) were assessed using zero–one inflated beta regression.
Results
The posterior probability of benefit comparing an accelerated versus a standard KRT initiation strategy for the primary endpoint suggested no important difference, regardless of the prior used (absolute difference of 0.13% [95% credible interval [CrI] − 3.30%; 3.40%], − 0.39% [95% CrI − 3.46%; 3.00%], and 0.64% [95% CrI − 2.53%; 3.88%] for neutral, optimistic, and pessimistic priors, respectively). There was a very low probability that the effect size was equal or larger than a consensus-defined minimal clinically important difference. Patients allocated to the accelerated strategy had a lower number of KRT-free days (median absolute difference of − 3.55 days [95% CrI − 6.38; − 0.48]), with a probability that the accelerated strategy was associated with more KRT-free days of 0.008. Hospital-free days were similar between strategies, with the accelerated strategy having a median absolute difference of 0.48 more hospital-free days (95% CrI − 1.87; 2.72) compared with the standard strategy and the probability that the accelerated strategy had more hospital-free days was 0.66.
Conclusions
In a Bayesian reanalysis of the STARRT-AKI trial, we found very low probability that an accelerated strategy has clinically important benefits compared with the standard strategy. Patients receiving the accelerated strategy probably have fewer days alive and KRT-free. These findings do not support the adoption of an accelerated strategy of KRT initiation
Regional Practice Variation and Outcomes in the Standard Versus Accelerated Initiation of Renal Replacement Therapy in Acute Kidney Injury (STARRT-AKI) Trial: A Post Hoc Secondary Analysis.
ObjectivesAmong patients with severe acute kidney injury (AKI) admitted to the ICU in high-income countries, regional practice variations for fluid balance (FB) management, timing, and choice of renal replacement therapy (RRT) modality may be significant.DesignSecondary post hoc analysis of the STandard vs. Accelerated initiation of Renal Replacement Therapy in Acute Kidney Injury (STARRT-AKI) trial (ClinicalTrials.gov number NCT02568722).SettingOne hundred-fifty-three ICUs in 13 countries.PatientsAltogether 2693 critically ill patients with AKI, of whom 994 were North American, 1143 European, and 556 from Australia and New Zealand (ANZ).InterventionsNone.Measurements and main resultsTotal mean FB to a maximum of 14 days was +7199 mL in North America, +5641 mL in Europe, and +2211 mL in ANZ (p p p p p p p p = 0.007).ConclusionsAmong STARRT-AKI trial centers, significant regional practice variation exists regarding FB, timing of initiation of RRT, and initial use of continuous RRT. After adjustment, such practice variation was associated with lower ICU and hospital stay and 90-day mortality among ANZ patients compared with other regions