We provide laboratory for students to design and complete experiment independently,and examine their operation ability in course of experiment.After accomplishing their experiments,the students must write a disquisition on it.Through this exploration experimentation,we have trained students scientific analysis ability and innovation ability and make them benefit form it in their future study and work.

Bacterial antibiotic resistance has become a serious problem facing the world today. The rapid spread of mobile genetic elements (MGEs) carrying antibiotic resistant genes between the same or different bacterial species has accelerated the formation of antibiotic resistance, posing a huge challenge to clinical treatment of bacterial infections. The insertion sequence (IS) is the simplest MGE, which encodes a transposase gene and has reverse terminal repeat sequences on both sides. The IS91 family is one of the 26 known insertion sequence family, with 34 members to its name. Recent studies have shown that many members of the IS91 family are strongly associated with antibiotic resistance. Therefore, this article will review the discovery and genetic characteristics of IS91 family, similarities and differences between IS91 and insertion sequence common region(ISCR), as well as their relationship with drug resistance and virulence gene transmission, so as to provide reference for future research on bacterial drug resistance.

Objective To explore the effect of a phased rehabilitation training programme to relieve shoulder dys-function in patients after neck dissection and to provide effective solutions for postoperative shoulder joint function recov-ery of patients.Methods This study has been reviewed and approved by the Ethics Committee,and informed consent has been obtained from patients.A phased rehabilitaiton training programme for the shoulder after neck dessection was developed through literature review and discussion,and 70 eligible patients from Hospital of Stomatology,Sun Yat-sen University from December 2020 to April 2021 were selected and randomly divided into the test group and control group(35 patients in each group).The control group underwent motor rehabilitation training from 6 weeks postoperative to 1 year after surgery,such as shoulder mobility and coordination training and small range of motion training of the neck,while the test group took part in a rehabilitation training program that included familiarization maneuver training,protective rehabilitation,exercise rehabilitation,and resistance training in the following four stages:preoperative,postop-erative general anesthesia and awake until the removal of stitches,the removal of stitches until 6 weeks after surgery,and 6 weeks after surgery until 1 year after surgery.The frequency of training in both groups was at least 3 days per week,and the length of each training session was 10-15 min.The intensity of exercise was 2-3 points on the Borg Conscious Ex-ercise Intensity Scale(i.e.,mild-to-moderate tachypnea or fatigue).The neck dissection injury index(NDII)was used to evaluate the quality of life related to shoulder joint function at four time points:preoperative,postoperative 3 months,postoperative 6 months,and postoperative 12 months.The higher the score,the better the quality of life.Results 28 cases in the test group and 32 cases in the control group completed a one-year follow-up.At 3 and 6 months postopera-tive,the NDII of the test group was significantly higher than that of the control group[3 months postoperative:test group(93.48±9.36)vs.control group(80.00±11.34)(P＜0.001),6 months postoperative:test group(98.21±4.76)vs.control group(90.70±9.12)(P＜0.001)];12 months after surgery,the NDII of the test group(97.23±4.88)was still higher than that of the control group(96.33±4.49),but the difference was not statistically significant(P=0.458).The difference in NDII scores among subjects at 3,6,and 12 months after surgery was statistically significant in each group(P＜0.001).Conclusion The application of the phased rehabilitation training method in neck dissection patients has a feasibility and could improve the quality of life of patients'shoulder joint function within 6 months after surgery.