Estimation of airship states and model uncertainties using nonlinear estimators

This Airships are lighter than air vehicles and due to their growing number of applications, they are becoming attractive for the research community. Most of the applications require an airship autonomous flight controller which needs an accurate model and state information. Usually, airship states are affected by noise and states information can be lost in the case of sensor's faults, while airship model is affected by model inaccuracies and model uncertainties. This paper presents the application of nonlinear and Bayesian estimators for estimating the states and model uncertainties of neutrally buoyant airship. It is considered that minimum sensor measurements are available, and data is corrupted with process and measurement noise. A novel lumped model uncertainty estimation approach is formulated where airship model is augmented with six extra state variables capturing the model uncertainty of the airship. The designed estimator estimates the airship model uncertainty along with its states. Nonlinear estimators, Extended Kalman Filter and Unscented Kalman Filter are designed for estimating airship attitude, linear velocities, angular velocities and model uncertainties. While Particle filter is designed for the estimation of airship attitude, linear velocities and angular velocities. Simulations have been performed using nonlinear 6-DOF simulation model of experimental airship for assessing the estimator performances. 1− uncertainty bound and error analysis have been performed for the validation. A comparative study of the estimator's performances is also carried out

A general strategy for selective detection of hypochlorous acid based on triazolopyridine formation

Triazolopyridines are an important kind of fused-ring compounds. A HOCl-promoted triazolopyridine formation strategy is reported here for the first time in which hypochlorous acid (HOCl) mildly and efficiently promotes the formation of 1,2,4-triazolo[4,3-a]pyridines NT1-NT6 from various 2-pyridylhydrazones N1-N6. N6, a rhodol-pyridylhydrazone hybrid, was developed into a fluorescent probe for the selective detection of HOCl, and successfully applied to probe endogenous HOCl in living cells and zebrafish in situ and in real time. The present intramolecular cyclization reaction is selective and atom-economical, thereby not only providing an important approach for the convenient synthesis of triazolopyridines, but also offering a general strategy for sensitive, selective and biocompatible detection of endogenous HOCl in complex biosystems.</p

Effects of a high-dose 24-h infusion of tranexamic acid on death and thromboembolic events in patients with acute gastrointestinal bleeding (HALT-IT): an international randomised, double-blind, placebo-controlled trial

Background: Tranexamic acid reduces surgical bleeding and reduces death due to bleeding in patients with trauma. Meta-analyses of small trials show that tranexamic acid might decrease deaths from gastrointestinal bleeding. We aimed to assess the effects of tranexamic acid in patients with gastrointestinal bleeding. Methods: We did an international, multicentre, randomised, placebo-controlled trial in 164 hospitals in 15 countries. Patients were enrolled if the responsible clinician was uncertain whether to use tranexamic acid, were aged above the minimum age considered an adult in their country (either aged 16 years and older or aged 18 years and older), and had significant (defined as at risk of bleeding to death) upper or lower gastrointestinal bleeding. Patients were randomly assigned by selection of a numbered treatment pack from a box containing eight packs that were identical apart from the pack number. Patients received either a loading dose of 1 g tranexamic acid, which was added to 100 mL infusion bag of 0·9% sodium chloride and infused by slow intravenous injection over 10 min, followed by a maintenance dose of 3 g tranexamic acid added to 1 L of any isotonic intravenous solution and infused at 125 mg/h for 24 h, or placebo (sodium chloride 0·9%). Patients, caregivers, and those assessing outcomes were masked to allocation. The primary outcome was death due to bleeding within 5 days of randomisation; analysis excluded patients who received neither dose of the allocated treatment and those for whom outcome data on death were unavailable. This trial was registered with Current Controlled Trials, ISRCTN11225767, and ClinicalTrials.gov, NCT01658124. Findings: Between July 4, 2013, and June 21, 2019, we randomly allocated 12 009 patients to receive tranexamic acid (5994, 49·9%) or matching placebo (6015, 50·1%), of whom 11 952 (99·5%) received the first dose of the allocated treatment. Death due to bleeding within 5 days of randomisation occurred in 222 (4%) of 5956 patients in the tranexamic acid group and in 226 (4%) of 5981 patients in the placebo group (risk ratio [RR] 0·99, 95% CI 0·82–1·18). Arterial thromboembolic events (myocardial infarction or stroke) were similar in the tranexamic acid group and placebo group (42 [0·7%] of 5952 vs 46 [0·8%] of 5977; 0·92; 0·60 to 1·39). Venous thromboembolic events (deep vein thrombosis or pulmonary embolism) were higher in tranexamic acid group than in the placebo group (48 [0·8%] of 5952 vs 26 [0·4%] of 5977; RR 1·85; 95% CI 1·15 to 2·98). Interpretation: We found that tranexamic acid did not reduce death from gastrointestinal bleeding. On the basis of our results, tranexamic acid should not be used for the treatment of gastrointestinal bleeding outside the context of a randomised trial

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

A spiropyran with low pK_a for tracking DNA G-quadruplexes and revealing the dissipation of ΔΨm with senescence using an in-situ switching strategy

The in-situ fluorescence triggering of bioprobes only using endogenous bioforces is an ideal non-destructive real-time detection method, which is of particular interest to improve the accuracy of clinical diagnosis and treatment. We have recently reported a strategy of spiropyran in-situ switching triggered by endogenous biological forces in vivo to develop optical probes for this purpose. However, such probes, as with all spiropyrans, are sensitive to lysosomal acidity. We here present a spiropyran-based fluorescent probe TANG with low pKa, which can recognize intranuclear DNA G4s in situ without the aid of exogenous light or chemicals and is as stable to lysosomal acidity due to a decreased pKa value (4.3). Interestingly, despite the stability to lysosomal pH environment, the TANG spiropyran can be opened in situ by the negative membrane potential of extranuclear mitochondria (ΔΨm), causing a ratiometric change in fluorescence signals and providing the in-situ and real-time tracking of ΔΨm. Of note, ratiometric imaging using TANG indicates that ΔΨm decreases gradually with cellular senescence, which is to the best of our knowledge the first visualization of such mitochondrion-related aging processes using a ratiometric imaging approach.</p

Dengue virus serotype 2 (DEN-2): the causative agent of 2011-Dengue epidemic in Pakistan

Abstract Introduction: Dengue virus (DENV) is an arthropod-borne virus that belonged to the Flaviviridae viral family. Four known serotypes DEN-1 through DEN-4 do exist and circulate in diverse geographical regions of the world causing epidemics. The management of dengue patients, and especially dengue hemorrhagic fever (DHF)/Dengue shock syndrome (DSS) cases, has been a challenge in Pakistan now days. Method: We have carried out a comprehensive study of the current outbreaks of dengue virus infection on molecular level with the aim to find out the common serotype/s of DENV responsible for this outbreak using PCR, real-time PCR and nucleotide sequencing targeting the C-prM gene junction. For this purpose total 1129 serum samples received between from start of August till end of November 2011 from all the major hospitals of Lahore, Punjab at Division of Molecular Virology, National Centre of Excellence in Molecular Biology (CEMB) University of the Punjab Lahore were utilized for the DENV diagnosis and serotypes/genotypes analysis. Results: Male female ratio of the suspected dengue patients was 2.4:1. Their mean age were 31.14 + 16.03 (SD) years ranging from 9 months to 90 years. Out of these 1129 serum samples, total 930 (82.37%) were found infected with DENV. Out of the 930 DENV RNA positive samples, 893 (96.02%) had DEN-2 Am. J. Biomed. Sci. 2012, 4(4), 307-315; doi: 10.5099/aj120400307 © 2012 by NWPII. All rights reserved. 308 and 37 (3.97%) sample had concurrent infection with serotypes 2 and 3. Conclusion: Based on the results of this study we conclude that DEN-2 is the responsible genotype for the current dengue epidemic that started from the beginning of year 2011 and is continuing till now. The additional serotype detected in the current study was serotype 3 that remained in very low frequency in Pakistan for last several decades