Twinning aspects and their efficient roles in wrought Mg alloys:A comprehensive review

Twinning is widely recognized as an effective and cost-efficient method for controlling the microstructure and properties of wrought magnesium(Mg)alloys.Specifically,twins play a crucial role in initiating dynamic recrystallization(DRX),while twin regions experience rapid recrystallization during static recrystallization(SRX).The activation of twinning can lead to changes in lattice orientation,significantly impacting the final texture in Mg alloys.The active roles of twinning are influenced by various factors during the activation process,and the mobility of twin boundaries(TB)can be amplified by stress effects,dislocation interactions,and thermal effects.Conversely,annealing treatments that involve proper segregation or precipitation on TBs serve to stabilize them,restraining their motion.Events such as segregation may also alter the twinning propensity in Magnesium-rare earth(Mg-RE)alloys.While{10–11}contraction twins(CT)and{10–11}-{10–12}double twins(DT)can promote dynamic recrystallization(DRX),they also pose a risk as potential sources of voids and cracks.Additionally,understanding the nucleation and growth mechanisms of twinning is crucial,and these aspects are briefly reviewed in this article.Considering the factors mentioned above,this article summarizes the recent research progress in this field,shedding light on advancements in recent eras.

Analysis of the Lost Circulation Problem

The well-known“lost circulation”problem refers to the uncontrolled flow of whole mud into a formation.In order to address the problem related to the paucity of available data,in the present study,a model is introduced for the lost-circulation risk sample profile of a drilled well.The model is built taking into account effective data(the Block L).Then,using a three-dimensional geological modeling software,relying on the variation function and sequential Gaussian simulation method,a three-dimensional block lost-circulation risk model is introduced able to provide relevant information for regional analyses.

Analysis of the Applicability of a Risk Quantitative Evaluation Method to High Temperature-Pressure Drilling Engineering

The optimization of methods for the quantitative evaluation of risks in drilling engineering is an effective means to ensure safety in situations where high temperature and high pressure blocks are considered.In such a context,this study analyzes the complexity of the drilled wells in such blocks.It is shown that phenomena such as well kick,loss,circulation,and sticking,are related to the imbalance of wellbore pressure.A method for risk quantitative evaluation is proposed accordingly.The method is used to evaluate the risk for 9 drilled wells.By comparing the predictions of the method with actual historical data related to these wells,it is found that the coincidence rate is about 95%.

Direct anti-HCV agents

Unlike human immunodeficiency virus(HIV)and hepatitis B virus(HBV),hepatitis C virus(HCV)infection is a curable disease.Current direct antiviral agent(DAA)targets are focused on HCV NS3/4A protein(protease),NS5 B protein(polymerase)and NS5 A protein.The first generation of DAAs includes boceprevir and telaprevir,which are protease inhibitors and were approved for clinical use in2011.The cure rate for genotype 1 patients increased from 45% to 70% when boceprevir or telaprevir was added to standard PEG-IFN/ribavirin.More effective and less toxic second generation DAAs supplanted these drugs by 2013.The second generation of DAAs includes sofosbuvir(Sovaldi),simeprevir(Olysio),and fixed combination medicines Harvoni and Viekira Pak.These drugs increase cure rates to over 90%without the need for interferon and effectively treat all HCV genotypes.With these drugs the "cure HCV"goal has become a reality.Concerns remain about drug resistance mutations and the high cost of these drugs.The investigation of new HCV drugs is progressing rapidly;fixed dose combination medicines in phase III clinical trials include Viekirax,asunaprevirtdaclatasvirtbeclabuvir,grazoprevirtelbasvir and others.

Anti-retroviral drugs: current state and development in the next decade

The pace of discovery of new antiretroviral(ARV) drugs has slowed, although the efficacy and safety of once-daily fixed dose combinations have been extensively investigated. Several traditional ARV drugs remain in phase Ⅲ clinical trials. This review summarizes current information on ARV drugs in phase Ⅲ clinical trials and focuses on the development of ARV drugs in the next decade.