This paper discusses application of multimedia and network technology in Laboratory Animal Science Teaching:We have set up multimedia courseware,made animal experiment video and built network course-learning system and a good teaching effect has been achieved.Then it analyzes the problems of multimedia and network technology in Laboratory Animal Science Teaching.

According to the principles of constructing evaluation index system in designed experiments,we formulated the content,designed the weights and established the evaluation index system in designed experiments based on analytical hierarchy process and Delphi.This system can assess students' cognition and attitudes,abilities of innovation,practice,teamwork and cooperation as well as scientific writing skills by providing objective and comprehensive evaluation criteria.

OBJECTIVETo explore the mechanism of matrine (Mat) induced human erythroleukemia TF-1 cell apoptosis and its effect on SALL4 expression.

METHODDifferent concentrations of the Mat (0.5, 1.0, 1.5, 2.0 g x L(-1) ) were cultured in vitro in TF-1 cells at different time (24, 48, 72 h). Cell proliferation was assayed by MTT. Cell cycle was determined by flow cytometry (FCM). Cell apoptosis was detected by Annexin V and PI double staining method. SALL4 mRNA expression was detected by reverse transcription RT-PCR (RTT-PCR).

RESULTAdministrated with Mat (0.5-2.0 g x L(-1)) after 24, 48, 72 h, the proliferation of TF-1 cells were inhibited (P < 0.01) , and in dose- and time-dependent manner. Half inhibitory concentration (IC50 ) was 1.0 g L(-1) at 48 h. After 48 h that the Mat acted on TF-1 cells, the proportion of G0/G1 phase cells increased while compared with the control group, and S phase cells decreased (P < 0.01). Apoptosis were 8.6% , 11.21%, 15.26% , 17.63%, which showed statistically significant difference (P < 0.01) compared with the control group (5.05%). RT-PCR results showed the ratio between SALL4 mRNA expression and beta-actin (internal reference) expression significantly decreased (P < 0.01) with Mat dose increased.

CONCLUSIONIn a certain range of concentration and time, Mat can inhibit TFT-1 cells proliferation. The mechanism is to make the cells G0/G1 phase blocked, to inhibit SALL4 gene expression and induce cell apoptosis.

Alkaloids ; pharmacology ; Antineoplastic Agents, Phytogenic ; pharmacology ; Apoptosis ; drug effects ; Cell Cycle ; drug effects ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Gene Expression ; drug effects ; Humans ; Leukemia, Erythroblastic, Acute ; drug therapy ; genetics ; metabolism ; physiopathology ; Quinolizines ; pharmacology ; Transcription Factors ; genetics ; metabolism

Objective To investigate the effects of down-regulation of Beclin 1, which is an autophagy regulatory molecule, expression induced by RNA interference on the proliferation and apoptosis in skin fibroblasts of naked mole rat. Methods The expression levels of Beclin 1 were detected after starvation or H2 O2 treatment.The fibroblasts were transi-ently transfected with specific siRNA targeting Beclin 1 and then screened by real-time PCR and Western blot.Cell prolifer-ation and apoptosis were determined using CCK-8 detection kit and flow cytometry ( FCM ) .The expressions of related genes were detected by Western blot.Results The expression of Beclin 1 gene at mRNA and protein levels was signifi-cantly lower in fibroblasts of the naked mole rat.Starvation and H2 O2 treatment induced changes of the Beclin 1 expression. Inhibition of Beclin 1 gene expression can inhibit cell proliferation and induce early and late apoptosis.The protein levels of p53, BAX, Bcl2, LC3B, p-AKT and mTOR were reduced after transient transfection with Beclin 1-siRNA.Conclusions The expression of Beclin 1 in fibroblasts of naked mole rat are changed in response to starvation or H2 O2 stimulation.Inhi-bition of Beclin 1 gene expression can inhibit cell proliferation and induce apoptosis.Therefore, Beclin1 gene may play a regulatory role in autophagy, proliferation and apoptosis in the skin fibroblasts of naked mole rat.

Inflammasome is the body of protein complex which is able to identify different stimulation signals and can in‐duce immune and inflammatory responses when it is activated .NLRP3 inflammasome has been extensively studied in the central nervous system .Microglia ,perivascular macrophages and meningeal macrophages express inflammasomes .The occurrence and development of acute brain infection ,aseptic acute brain injury ,Parkinson disease and Alzheimer disease are closely related to inflammasomes .Based on mechanisms exploration of the inflammasome′s role in the central nervous system disorders ,its tar‐get drug research and development will be greatly addressed in the future .

The CRISPR-Cas (clustered regularly interspaced short palindromic repeats and CRISPR-associated) system is an "adaptive immune system" found in the genomes of bacteria and archaea which is mediated by RNA and resists foreign nucleic acid invasion.Take advantage of specific recognition of target nucleic acid, CRISPR-Cas system can efficiently edit their target site or accurately regulate gene expression, and now have been developed into a powerful tool for gene editing.According to the different compositions of the effector complex, the system has been divided into two categories: class 1 (type I, type IV, and type III) and class 2 (type II, type V, and type VI).Class 2 system, like the CRISPR-Cas9, is widely used in basic research due to the earliest discovery and best research.However, class 1 has not been maturely developed and utilized though it makes up 90% of the entire CRISPR-Cas system.In this essay, the classification of subtype, the assembly of Cascade complex, the cleavage and degradation mechanism of Cas3, and the application in gene editing of class 1 type I CRISPR-Cas system will be discussed and summarized to provide new ideas and methods for further mechanism studying and application of this category.

Objective To investigate the clinical effect of free posterior interosseous artery perforator flap combined with muscle fascia for repairing soft tissue and extensor tendon defect of hand.Methods Fifteen cases of hand skin soft tissue and extensor tendon defect admitted to Ningbo No.6 Hospital from December 2017 to December 2020 were repaired with free posterior interosseous artery perforator flap combined with extensor carpi ulnaris muscle fascia transplantation,and curative effect was observed.Results All flaps survived and patients were followed up for 6-24 months.The texture and thickness of the flap were satisfactory,and the recovery of the finger extension and flexion function were good.The excellent and good rate of hand tendon repair was 66.7%.In three cases with nerve anastomosis,the skin flap sensation recovered to S3.Conclusion The free posterior interosseous artery perforator flap combined with muscle fascia has a good clinical effect in repairing hand skin soft tissue and tendon defect.