MXene Lubricated Tribovoltaic Nanogenerator with High Current Output and Long Lifetime

Tribovoltaic nanogenerators(TVNGs)have the characteristics of high current density,low matched impedance and continuous output,which is expected to solve the problem of power supply for small electronic devices.However,wear occurrence in friction interface will seriously reduce the performance of TVNGs as well as lifetime.Here,we employ MXene solution as lubricate to improve output current density and lifetime of TVNG simultaneously,where a high value of 754 mA m^(-2)accompanied with a record durability of 90,000 cycles were achieved.By comparing multiple liquid lubricates with different polarity,we show that conductive polar liquid with MXene as additive plays a crucial role in enhancing the electrical output performance and durability of TVNG.Moreover,the universality of MXene solution is well demonstrated in various TVNGs with Cu and P-type Si,and Cu and N-GaAs as material pairs.This work may guide and accelerates the practical application of TVNG in future.

Geodetic monitoring of the Changbaishan volcano activity and its relationship with earthquakes,1999-2017

The major earthquakes often trigger unrest of surrounding volcanic magma chambers.In recent years,three major earthquakes occurred around the Changbaishan volcano,but it was unclear whether these earthquakes triggered the unrest of the magma chamber.Based on geodetic data,we analyzed the volcanic activity according to the Global Position System(GPS)and leveling sites time-series and reestimated the location and volume change of magma chamber from 2002 to 2005.Meanwhile,we calculated the dilatational strain variations of the deep magma chamber resulting from coseismic deformations caused by the 1999 Mw7.0 and 2002 Mw7.3 Wangqing deep earthquakes and the 2011 Mw9.0 Tohoku-oki earthquake.Our results show:(1)Changbaishan has experienced four stages of unrest since 1999,and the biggest unrest of the shallow magma chamber occurred from 2002 to 2005;(2)the parameters of the shallow magma chamber simulated by the Mogi and Point Compound Dislocation Model(p DCM)show that the magma chamber is located in the northern part of the crater,with a depth of approximately 7 km.The volume of the magma chamber increased by 25-28×10^(6) m from 2002 to2005;(3)the strain variation beneath the Changbaishan volcano corresponding to the 1999 Wangqing earthquake was small.The 2002 Wangqing earthquake produced an expansion strain of about 4.4 nanostrain on the magma chamber at a depth of 550 km,and probably promoted the unrest of the Changbaishan volcano.The 2011 Tohoku earthquake induced the expansion of the shallow magma chamber and compression of the deep magma chamber.Although this event promoted shallow magma unrest,it inhibited deep magma unrest.This may explain why the Changbaishan did not show obvious unrest after the 2011 Tohoku earthquake.Therefore,more attention should be paid to earthquakes that can promote deep magma unrest in the Changbaishan volcano.

Current trends in drug metabolism and pharmacokinetics

Pharmacokinetics(PK)is the study of the absorption,distribution,metabolism,and excretion(ADME)processes of a drug.Understanding PK properties is essential for drug development and precision medication.In this review we provided an overview of recent research on PK with focus on the following aspects:(1)an update on drug-metabolizing enzymes and transporters in the determination of PK,as well as advances in xenobiotic receptors and noncoding RNAs(ncRNAs)in the modulation of PK,providing new understanding of the transcriptional and posttranscriptional regulatory mechanisms that result in inter-individual variations in pharmacotherapy;(2)current status and trends in assessing drug-drug interactions,especially interactions between drugs and herbs,between drugs and therapeutic biologies,and microbiota-mediated interactions:(3)advances in understanding the effects of diseases on PK,particularly changes in metabolizing enzymes and transporters with disease progression;(4)trends in mathematical modeling including physiologically-based PK modeling and novel animal models such as CRISPR/Cas9-based animal models for DMPK studies:(5)emerging non-classical xenobiotic metabolic pathways and the involvement of novel metabolic enzymes,especially non-P450s.Existing challenges and perspectives on future directions are discussed,and may stimulate the development of new research models,technologies,and strategies towards the development of better drugs and improved clinical practice.

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.

Evaluation of the efficacy and safety of hydroxychloroquine in comparison with chloroquine in moderate and severe patients with COVID-19

Dear Editor,Since December 2019,severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)has been rapidly spreading worldwide.Hydroxychloroquine and chloroquine are candidates for the treatment of coronavirus disease 2019(COVID-19)owing to its antiviral effect and immunomodulation properties.

Thermodynamic analysis of reaction pathways and equilibrium yields for catalytic pyrolysis of naphtha

The chain length and hydrocarbon type significantly affect the production of light olefins during the catalytic pyrolysis of naphtha.Herein,for a better catalyst design and operation parameters optimization,the reaction pathways and equilibrium yields for the catalytic pyrolysis of C_(5-8)n/iso/cyclo-paraffins were analyzed thermodynamically.The results revealed that the thermodynamically favorable reaction pathways for n/iso-paraffins and cyclo-paraffins were the protolytic and hydrogen transfer cracking pathways,respectively.However,the formation of light paraffin severely limits the maximum selectivity toward light olefins.The dehydrogenation cracking pathway of n/iso-paraffins and the protolytic cracking pathway of cyclo-paraffins demonstrated significantly improved selectivity for light olefins.The results are thus useful as a direction for future catalyst improvements,facilitating superior reaction pathways to enhance light olefins.In addition,the equilibrium yield of light olefins increased with increasing the chain length,and the introduction of cyclo-paraffin inhibits the formation of light olefins.High temperatures and low pressures favor the formation of ethylene,and moderate temperatures and low pressures favor the formation of propylene.n-Hexane and cyclohexane mixtures gave maximum ethylene and propylene yield of approximately 49.90%and 55.77%,respectively.This work provides theoretical guidance for the development of superior catalysts and the selection of proper operation parameters for the catalytic pyrolysis of C_(5-8)n/iso/cyclo-paraffins from a thermodynamic point of view.