The Therapeutic Effect of Traditional Chinese Medicine on Inflammatory Diseases Caused by Virus, Especially on Those Caused by COVID-19

Inflammasomes are large multimolecular complexes best recognized because of their ability to control activation of caspase-1, which in turn regulates the maturation of interleukin-18 (IL-18) and interleukin-1 β (IL-1β). IL-1β was originally identified as a pro-inflammatory cytokine, capable of inducing local and systemic inflammation as well as a fever response reaction in response to infection or injury. Excessive production of IL-1β is related to inflammatory and autoimmune diseases. Both coronavirus disease 2019 (COVID-19) and severe acute respiratory syndrome (SARS) are characterized by excessive inflammatory response. For SARS, there is no correlation between viral load and worsening symptoms. However, there is no specific medicine which is available to treat the disease. As an important part of medical practice, TCM showed an obvious therapeutic effect in SARS-CoV-infected patients. In this article, we summarize the current applications of TCM in the treatment of COVID-19 patients. Herein, we also offer an insight into the underlying mechanisms of the therapeutic effects of TCM, as well as introduce new naturally occurring compounds with anti-coronavirus activity, in order to provide a new and potential drug development strategy for the treatment of COVID-19.

Allostery in the nitric-oxide dioxygenase mechanism of flavohemoglobin

The substrates O2 and NO cooperatively activate the NO dioxygenase function of Escherichia coli flavohemoglobin. Steady-state and transient kinetic measurements support a structure-based mechanistic model in which O2 and NO movements and conserved amino acids at the E11, G8, E2, E7, B10 and F7 positions within the globin domain control activation. In the cooperative and allosteric mechanism, O2 migrates to the catalytic heme site via a long hydrophobic tunnel and displaces LeuE11 away from the ferric iron, which forces open a short tunnel to the catalytic site gated by the ValG8/IleE15 pair and LeuE11, which NO permeates and leverages upon to trigger the CD loop to furl, which moves the E and F-helices and switches an electron transfer gate formed by LysF7, GlnE7 and water, which allows FADH2 to reduce the ferric iron, which forms the stable ferric-superoxide-TyrB10/GlnE7 complex, which reacts with internalized NO with a bimolecular rate constant of 1010 M-1 s-1 forming nitrate, which migrates to the CD loop and unfurls the spring-like structure. To restart the cycle, LeuE11 toggles back to the ferric iron. Actuating electron transfer with O2 and NO movements averts irreversible NO poisoning and reductive inactivation of the enzyme. Together, structure snapshots and kinetic constants provide glimpses of intermediate conformational states, time scales for motion, and associated energies.

Potassium Speciation and Distribution for the K2CO3 Additive-Induced Activation/Deactivation of Olivine During Gasification of Woody Biomass

<p>The GoBiGas plant, which comprises a 32-MW_thdual fluidized bed gasifier, was constructed as a demonstration unit for converting biomass to biomethane via gasification. On several occasions during the commissioning of the plant, low activity of the olivine bed generated a high content of tar in the produced gas, which was deleterious to the downstream equipment. The problem was attributed to a deficiency of ash constituents, and the solution was to control activation of the bed material through the addition of K₂CO₃to the process. This enabled extended operational periods without tar-related issues. The achieved activity could be lost during interrupted operation at which time the activation procedure had to be repeated. In the present paper analysis of the bed material samples extracted upon activation and after loss of activity using Scanning Electron Microscopy coupled with Energy Dispersive X-ray spectroscopy (SEM-EDS) showed similar morphologies for the ash layers formed around the olivine particles. The observed differences mainly related to the distributions of potassium (K) across the layers. Furthermore, surface analysis showed differences in K speciation within the outer regions. K solubility tests and X-ray photoelectron spectroscopy analyses indicated that K was present as an oxide/hydroxide rather than as a silicate on the surface of the active olivine. The presented results are of major relevance for the operation of dual fluidized bed gasifiers with fuels that are potassium-lean when ash components need to be supplied as additives </p>

Potassium Speciation and Distribution for the K2CO3 Additive-Induced Activation/Deactivation of Olivine During Gasification of Woody Biomass

<p>The GoBiGas plant, which comprises a 32-MW_thdual fluidized bed gasifier, was constructed as a demonstration unit for converting biomass to biomethane via gasification. On several occasions during the commissioning of the plant, low activity of the olivine bed generated a high content of tar in the produced gas, which was deleterious to the downstream equipment. The problem was attributed to a deficiency of ash constituents, and the solution was to control activation of the bed material through the addition of K₂CO₃to the process. This enabled extended operational periods without tar-related issues. The achieved activity could be lost during interrupted operation at which time the activation procedure had to be repeated. In the present paper analysis of the bed material samples extracted upon activation and after loss of activity using Scanning Electron Microscopy coupled with Energy Dispersive X-ray spectroscopy (SEM-EDS) showed similar morphologies for the ash layers formed around the olivine particles. The observed differences mainly related to the distributions of potassium (K) across the layers. Furthermore, surface analysis showed differences in K speciation within the outer regions. K solubility tests and X-ray photoelectron spectroscopy analyses indicated that K was present as an oxide/hydroxide rather than as a silicate on the surface of the active olivine. The presented results are of major relevance for the operation of dual fluidized bed gasifiers with fuels that are potassium-lean when ash components need to be supplied as additives </p>

Integrated Steering and Braking Control System for Collision Avoidance by Using Virtual Repulsive Force Field Method

Advanced Driver Assistance Systems (ADAS) and autonomous driving systems are being enhanced to deal with various types of collision avoidance use-case scenarios. To handle those complicated scenarios, a unified two-dimensional planar motion control methodology assuming virtual repulsive force from obstacles is introduced, which is physically interpretable and comprehensible. The direction and magnitude of virtual repulsive force are determined considering the orientation of obstacle surface planes and the friction limit between tires and road surface respectively. Applying the concept of virtual repulsive force field, the collision avoidance path can be derived from geometrical relationship and the control activation points can be obtained as algebraic solutions. By using a simple particle mass model, the formulation for path and control activation point is described. The simulation is conducted against not only in the case of a straight roadway but also in the case of a curve roadway. By designing feedforward and feedback controllers based on a two-wheel vehicle dynamics model, the effectiveness of the proposed method is verified and the feasibility of controller implementation for actual vehicle is also investigated.