Multidrug resistance (MDR) is one of the main reasons for failure in clinical treatment of cancer.A variety of different mechanisms involves in the occurrence and during the development of MDR.Exploiting the corresponding reversal drugs according to the mechanisms is the major route of solving MDR problems clinically.In this article,research of MDR mechanisms,at home and abroad is reviewed.

Objective:To investigate the mid- and long-term training effect of deliberate practice combined with intensive training in cardiopulmonary resuscitation (CPR) teaching for nurses receiving standardized training.Methods:A total of 160 nurses who received the first year of standardized training in Guangdong Provincial Hospital of Traditional Chinese Medicine from July 2020 to March 2021 were enrolled as subjects, and they were randomly divided into experimental group and control group, with 80 nurses in each group. The nurses in the control group received the mode of single deliberate practice, and those in the experimental group received deliberate practice combined with intensive training at months 0, 3, and 6. Assessment was performed for the two groups before and after training,with objective indicators and subjective evaluation as the assessment criteria. Objective score was determined by the immediate objective feedback provided by the electronic display of Resusci Anne ? QCPR, and subjective score was determined by the same group of examiners based on the evaluation of cardiopulmonary resuscitation performed by trainees,including environment evaluation, judgment of consciousness, judgment of respiration, initiation of emergency treatment system, re-evaluation after resuscitation, and overall evaluation. SPSS 18.0 was used for the independent samples t-test, the non-parametric test, and the chi-squares test. Results:After training, there were significant differences between the experimental group and the control group in the objective indicators of the percentage of correct compression (CC%) [85.500 (77.50, 93.00) vs. 81.00 (71.75, 89.00), Z=-2.49, P=0.013] and the proportion of correct ventilation (V%) [84.00 (75.00, 92.75) vs. 80.00 (64.00, 90.25), Z=-2.15, P=0.031]. Both groups had significant improvements in objective and subjective indicators after training (all P<0.05). Conclusions:Deliberate practice combined with intensive training at an interval of 3 months can effectively improve the mid- and long-term CPR skills of nurses receiving standardized training and is more suitable for high-level muscle memory training.