Pharmacotherapy in Coronavirus Disease 2019 and Risk of Secondary Infections: A Single-Center Case Series and Narrative Review

OBJECTIVES: Since the onset of the coronavirus disease 2019 pandemic, immune modulators have been considered front-line candidates for the management of patients presenting with clinical symptoms secondary to severe acute respiratory syndrome coronavirus 2 infection. Although heavy emphasis has been placed on early clinical efficacy, we sought to evaluate the impact of pharmacologic approach to coronavirus disease 2019 within the ICU on secondary infections and clinical outcomes. DATA SOURCES: PubMed (inception to March 2021) database search and manual selection of bibliographies from selected articles. STUDY SELECTION AND DATA EXTRACTION: Articles relevant to coronavirus disease 2019, management of severe acute respiratory syndrome coronavirus 2-associated respiratory failure, and prevalence of secondary infections with pharmacotherapies were selected. The MeSH terms COVID-19, secondary infection, SARS-CoV-2, tocilizumab, and corticosteroids were used for article identification. Articles were narratively synthesized for this review. DATA SYNTHESIS: Current data surrounding the use of tocilizumab and/or corticosteroids for coronavirus disease 2019 management are limited given the short follow-up period and conflicting results between studies. Further complicating the understanding of immune modulator role is the lack of definitive understanding of clinical impact of the immune response in coronavirus disease 2019. CONCLUSIONS: Based on the current available literature, we suggest prolonged trials and follow-up intervals for those patients managed with immune modulating agents for the management of coronavirus disease 2019

The role of retrograde intraflagellar transport in flagellar assembly, maintenance, and function

The maintenance of flagellar length is believed to require both anterograde and retrograde intraflagellar transport (IFT). However, it is difficult to uncouple the functions of retrograde transport from anterograde, as null mutants in dynein heavy chain 1b (DHC1b) have stumpy flagella, demonstrating solely that retrograde IFT is required for flagellar assembly. We isolated a Chlamydomonas reinhardtii mutant (dhc1b-3) with a temperature-sensitive defect in DHC1b, enabling inducible inhibition of retrograde IFT in full-length flagella. Although dhc1b-3 flagella at the nonpermissive temperature (34 degrees C) showed a dramatic reduction of retrograde IFT, they remained nearly full-length for many hours. However, dhc1b-3 cells at 34 degrees C had strong defects in flagellar assembly after cell division or pH shock. Furthermore, dhc1b-3 cells displayed altered phototaxis and flagellar beat. Thus, robust retrograde IFT is required for flagellar assembly and function but is dispensable for the maintenance of flagellar length. Proteomic analysis of dhc1b-3 flagella revealed distinct classes of proteins that change in abundance when retrograde IFT is inhibited

Robust Feedback Control For A Class Of Uncertain Mimo Nonlinear Systems

In this paper, a continuous feedback tracking controller is developed for a class of high-order multi-input multi-output (MIMO) nonlinear systems with an input gain matrix that has nonzero leading principal minors but can be nonsymmetric. Under the mild assumption that the signs of the leading minors of the control input gain matrix are known, the controller yields locally uniformly ultimately bounded (UUB) tracking while compensating for unstructured uncertainty in both the drift vector and the input matrix. First, a full-state feedback controller is designed based on limited assumptions on the structure of the system nonlinearities, and the singularity-free controller is proven to yield locally UUB tracking through a Lyapunov-based analysis. Then, it is shown that an output feedback control can be designed based on a high-gain observer. Simulation results are provided to illustrate the performance of the proposed control algorithm. © 2008 IEEE

A Novel Path Planning And Control Framework For Passive Resistance Therapy With A Robot Manipulator

In this article, we present a paradigm for safe path generation and control for a robotic manipulator such that it provides programmable passive resistance therapy to patients with deficits in the upper extremities. When the patient applies an interaction force at the robot\u27s end-effector, a dynamic path generator time parameterises any therapist-specified contour in the robot\u27s workspace-thus, the robot mimics the dynamics of a passive impedance whose anisotropy vector can be continuously reconfigured. The proposed algorithm is easily implementable because it is robust to uncertainty in the robot dynamics. Moreover, the proposed strategy also guarantees user safety by maintaining the net flow of energy during the human robot interaction from the user towards the manipulator

Nonlinear Tracking Control of an Underactuated Spacecraft

In this paper, we design a nonlinear controller for the kinematic model of an underactuated rigid spacecraft that ensures uniform, ultimately bounded (UUB) tracking provided the initial errors are selected sufficiently small. The result is achieved via a judicious formulation of the spacecraft kinematics and the novel design of a Lyapunov-based controller. We also discuss how standard backstepping control techniques can be fused with the kinematic controller to solve the full-order regulation problem for an axisymmetric spacecraft

Metabolic bypass of the tricarboxylic acid cycle during lipid mobilization in germinating oilseeds - Regulation of NAD(+)- dependent isocitrate dehydrogenase versus fumarase

Biosynthesis of sucrose from triacylglycerol requires the bypass of the CO2-evolving reactions of the tricarboxylic acid (TCA) cycle. The regulation of the TCA cycle bypass during lipid mobilization was examined. Lipid mobilization in Brassica napus wa

Particle Filter-Based Robust Visual Servoing for UCF-MANUS-An Intelligent Assistive Robotic Manipulator

A particle filter based tracking scheme is proposed to robustify visual servoing of objects in the UCF-MANUS camera-in-hand vision setup. Instead of simply fusing global and local information, a concatenation of the two sources of information is proposed here which enables the combination of the two independent measurements with a synergistic collaboration between them. A novel overlap metric to encode the degree and quality of overlap between two arbitrarily shaped Regions of Interest (ROIs) is defined to facilitate the prior and posterior pdfs in the particle filter setup.A sub-ROI is defined and utilized in the observation step to facilitate the global target detection. Based on extensive experimental results under a variety of scenarios obtained by using the UCF-MANUS assistive robotic testbed, it is seen that the proposed particle filter based fusion approach is superior to other non-fused global detection or local tracking approaches. The efficacy of the proposed approach has also been verified using standard data sets. Finally, robustification of a hybrid visual servoing technique is shown by implementing the proposed particle-filter based tracker during closed-loop operation in real-time

Setpoint Regulation Of Continuum Robots Using A Fixed Camera

In this paper, we investigate the problem of measuring the shape of a continuum robot manipulator using visual information from a fixed camera. Specifically, we capture the motion of a set of fictitious planes, each formed by four or more feature points, defined at various strategic locations along the body of the robot. Then, utilizing expressions for the robot forward kinematics as well as the decomposition of a homography relating a reference image of the robot to the actual robot image, we obtain the three-dimensional shape information continuously. We then use this information to demonstrate the development of a kinematic controller to regulate the manipulator end-effector to a constant desired position and orientation. © 2007 Cambridge University Press