Novel patterns for drug synergistic mechanism research

Drug combination based on synergistic effect is commonly used in clinical practice,especially in the application of traditional medicine.Exploring the combination mechanism could help to better utilize this synergistic advantage.However,current research focuses more on the efficacy enhancing of drugs,while ignoring the toxicity reducing effects.Here,we established two drug synergy patterns based on the different situations of drugs and targets,in order to better illuminate the synergistic mechanism of drugs.

Effects of Ni content and tempering temperatures on microstructure and properties of medium-carbon cast steel

The microstructure evolution and properties of medium-carbon cast steel alloyed with different Ni contents after tempering at various temperatures have been investigated.The addition of 0.47-1.59 wt.%Ni content results in the formation of 16%-36% retained austenite(RA).The blocky and irregular-polygonal RA mainly forms along the prior austenite grain boundaries,and the tempering temperature does not affect the RA content.The hardness of medium-carbon cast steel is affected by the precipitation of carbides and the hardness of martensite.Excessive RA content is the main cause of intergranular impact rupture and low impact energy.The long-strip carbides formed after tempering at 320℃ would further reduce the impact energy of medium-carbon cast steel.When tempering at 220 and 380℃,the increase in impact energy is attributed to the formation of rod-like and spherical carbides and the low-carbon martensite.For the medium-carbon cast steel with high impact energy,its impact-abrasive wear resistance is more excellent.Micro-cutting and delamination are the primary wear mechanisms.

High-temperature fatigue behavior of 15CrNbTi ferritic stainless steel

In order to investigate the high-temperature fatigue and fatigue-creep behavior of 15CrNbTi ferritic stainless steel at 800°C,fatigue tests without holding time in laboratory air and with 10 s holding time induced at maximum cyclic stress under argon atmosphere were conducted on an electrohydraulic servo fatigue testing machine.In addition,the morphologies of fatigue fracture surfaces were observed,and the precipitates and dislocation substructures were characterized.The experimental results show that the fatigue limit of 15CrNbTi ferritic stainless steel is 30 MPa at 800°C.The fatigue life of the experimental steel obviously decreases if holding time of 10 s is introduced at maximum cyclic stress.Under two test conditions,the fatigue cracks transgranularly initiate at the free surface of fatigue specimens and then propagate in a transgranular mode.It is dem on strated that three kinds of precipitates inclu ding(Nb,Ti)C phase,Fe2Nb phase and Fe3Nb3C phase can be observed in 15CrNbTi ferritic stainless steel,and the Fe2Nb and Fe3Nb3C phases are mainly precipitated during the fatigue tests.In the fatigue deformation area,both dislocation tangles and dislocation arrays are observed.Furthermore,the sub-grains which form during the cycling deformation with holding time of 10 s are also found.Moreover,the formation of sub-grains leads to the deterioration of the fatigue life of 15CrNbTi steel.