Dynamic Flow Control Strategies of Vehicle SCR Urea Dosing System

Selective Catalyst Reduction（SCR）Urea Dosing System（UDS）directly affects the system accuracy and the dynamic response performance of a vehicle.However,the UDS dynamic response is hard to keep up with the changes of the engine＇s operating conditions.That will lead to low NO_χconversion efficiency or NH_3 slip.In order to optimize the injection accuracy and the response speed of the UDS in dynamic conditions,an advanced control strategy based on an air-assisted volumetric UDS is presented.It covers the methods of flow compensation and switching working conditions.The strategy is authenticated on an UDS and tested in different dynamic conditions.The result shows that the control strategy discussed results in higher dynamic accuracy and faster dynamic response speed of UDS.The inject deviation range is improved from being between-8%and 10%to-4%and 2%and became more stable than before,and the dynamic response time was shortened from 200 ms to 150 ms.The ETC cycle result shows that after using the new strategy the NH_3 emission is reduced by 60%,and the NO_χemission remains almost unchanged.The trade-off between NO_χconversion efficiency and NH_3 slip is mitigated.The studied flow compensation and switching working conditions can improve the dynamic performance of the UDS significantly and make the UDS dynamic response keep up with the changes of the engine＇s operating conditions quickly.

Dose selection of chloroquine phosphate for treatment of COVID-19 based on a physiologically based pharmacokinetic model

Chloroquine(CQ)phosphate has been suggested to be clinically effective in the treatment of coronavirus disease 2019(COVID-19).To develop a physiologically-based pharmacokinetic(PBPK)model for predicting tissue distribution of CQ and apply it to optimize dosage regimens,a PBPK model,with parameterization of drug distribution extrapolated from animal data,was developed to predict human tissue distribution of CQ.The physiological characteristics of time-dependent accumulation was mimicked through an active transport mechanism.Several dosing regimens were proposed based on PBPK simulation combined with known clinical exposure-response relationships.The model was also validated by clinical data from Chinese patients with COVID-19.The novel PBPK model allows indepth description of the pharmacokinetics of CQ in several key organs(lung,heart,liver,and kidney),and was applied to design dosing strategies in patients with acute COVID-19(Day 1:750 mg BID,Days 2-5:500 mg BID,CQ phosphate),patients with moderate COVID-19(Day 1:750 mg and 500 mg,Days 2-3:500 mg BID,Days 4-5:250 mg BID,CQ phosphate),and other vulnerable populations(e.g.,renal and hepatic impairment and elderly patients,Days 1-5:250 mg BID,CQ phosphate).A PBPK model of CQ was successfully developed to optimize dosage regimens for patients with COVID-19.

Bias in multiple-treatments meta-analysis： a case on comparative efficacy and tolerability of 15 antipsychotic drugs for schizophrenia

Multiple-treatments meta-analysis is thought to be a feasible method to compare the efficacy and safety among different treatments, especially when there was no head-to-head research among some treatments. But sometimes some conclusions are inconsistent with the clinical experience. Recently, we read a multiple-treatment meta-analysis finished by Stefen Leucht et al, which was published in Lancet） The authors summarized the results of the RCT studies on 15 antipsychotics commonly used in practice; they also horizontally compared the efficacy and safety profile by the recta-analysis. We believe that the results provide more solid evidence for the rational usage of antipsychotics to the psychiatrists, also for the government to distribute health resources in a more reasonable way.

A dual-targeted multifunctional nanoformulation for potential prevention and therapy of Alzheimer’s disease

Antioxidation and adjustable treatment strategies are critical for the effective treatment of Alzheimer’s disease(AD).Here,we design a dual-targeted Prussian blue nanoformulation(PTCN)that can cross the blood-brain barrier and target amyloid beta aggregates further exert antioxidant effects.An adjustable gradient dosing strategy with PTCN is used for the first time to design the preventive and therapeutic trials based on the severity of oxidative stress at different AD stages.The results show that PTCN could effectively ameliorate AD-related pathological processes,improve the cognitive decline,and rescue hippocampal atrophy of APP/PS1 mice in both preventive and therapeutic trials.Altogether,PTCN provided here is a successful combination of three traditional biomaterials with good biosafety,which has broad prospects for the early prevention,mild remission,and late treatment of AD,and is expected to be developed into personalized therapeutic drugs and healthcare products for clinical AD in the future.