80 extracted human mandible premolars were divided into 10 groups(n =8)based on the post with different tilted angles(0°, buccal 15°and 30°,ligual 15°and 30°).The samples in experiment group were restored with fiber post while in the control group with cast post.Then all the teeth were restored with cast crown and bonded by glass ionomer.Compressive load with the speed of 1.0 mm/min was ap-plied to the restored teeth with a universal material testing machine until failure and the fracture modes were observed.The fracture load of fi-ber post and cast post restoration with the same tilted angles was similar(P >0.05).The main fracture mode of the teeth in all groups was unfavorable tooth fracture.No significant interaction was observed(P =0.217)between the 2 kinds of post and angulation of tilted teeth.

Objective To evaluate the clinical effect of immediate implant restoration in lower posterior teeth . Methods 31 XIVE implants were placed in lower posterior teeth of 31 patients.The temporary fixed resin crowns were fabricated immediately and final restorations were finished in 3~4 months.The control group used nonsub-merged implants and were restored with final crowns in 3~4 months.The tracking survey was taken from 12 to 24 months after final restoration .The patient satisfaction , papilla index score ( PIS ) and implant survival rate were eval-uated between the two groups .Results PIS of patients with immediate restoration reached (2.35 ±0.70) in aver-age compared(1.84 ±0.74) in control group.The patient satisfaction reached (91.5 ±7.5) with immediate resto-ration, compared with VAS score in average of(85.8 ±8.1) in control group.All implants in both groups achieved osseointegration and received 100% survival rate .Conclusion With proper technique in surgical and restoration procedure , immediate restoration after implant insertion in posterior madible has similar clinical success compared with delayed restoration .

The incorporation of site-specific recombination systems can help to overcome bottlenecks in livestock transgenic technology. For evaluating the efficiency of Cre/lox mediated DNA recombination in embryos and somatic cells, a working model was established using rat mammary carcinoma cell line SHZ-88, aimed at creation of and use repeatedly of selected "friendly loci" in transgenic livestock. An integration vector pTE-lox2272-DsRed-loxP-GFP-loxP, which red fluorescence gene DsRed served as the first target gene and green fluorescence gene GFP as marker gene, was constructed for introduction of acceptor loci in genome. At the same time a replacement vector pT-lox2272-neo-loxP in which Neo coding sequence served as the second target gene was also constructed for replacing DsRed gene. Transgenic cell clones were produced by electroporating SHZ-88 cell with the integration vector. Cells from three transgenic clones selected randomly were further amplified and were then co-electroporated with the replacement vector as well as cre gene. Analysis of the expression patterns of DsRed and GFP indicated that among the 1 070 cell colonies the efficiency on marker GFP deletion was 91.1% and the efficiency on gene replacement was 29.3%. Molecular analysis by PCR and Southern blotting confirmed that the color patterns as expressed by cell colonies could represent the actual molecular events. This working model mediated by Cre/lox system should be useful for the improvement of the present animal transgenic technology.

Objective To study the effects of radical surgical treatment for early esophageal cancer, and to investigate the prevention and cure of their complications,cancer recurrence and metastasis.Methods Treatments of 240 patients with early esophageal cancer of Chinese PLA General Hospital from January 2005 to January 2009 were retrospectively analyzed.The patients were treated by left thoracotomy,thoracic or cervical mechanical anastomosis surgical methods of treatment.Their postoperative adverse reactions,complications and 1 -,3-,5-year survival rates were observed and analyzed.Results The surgical resection rate was 1 00.00%. Complications included postoperative pulmonary infection (1 2 patients,5.00%), cardiac arrhythmias (1 patient,0.42%),delayed gastric emptying (2 patients,0.83%),pleural hemorrhage (1 patient, 0.42%),recurrent laryngeal nerve injury (2 patients,0.83%)and anastomotic fistula (1 patient,0.42%). One-year,3-year and 5-year survival rates after surgery were 1 00.00% (240 /240),97.9% (235 /240)and 95.8% (230 /240)respectively.The main causes of postoperative death were tumor recurrence and metastasis. Conclusion Timely surgery for early esophageal cancer can bring in good effect and long-term outcome,with little complication,which can obtain a good forward curative effect.

Traumatic rib fractures are the most common injury in thoracic trauma. Previously，the patients with traumatic rib fractures were mostly treated non-surgically，of which 50%，especially those combined with flail chest presented chronic pain or chest wall deformities and over 30% had long-term disabilities，being unable to retain a full-time job. In the past two decades，thanks to the development of internal fixation material technology，the surgical treatment of rib fractures has achieved good outcomes. However，there are still some problems in clinical treatment，including inconsistency in surgical treatment and quality control in medical services. The current consensuses on the management of regional traumatic rib fractures published at home and abroad mainly focus on the guidance of the overall treatment decisions and plans，and relevant clinical guidelines abroad lacks progress in surgical treatment of rib fractures in recent years. Therefore，the Chinese Society of Traumatology affiliated to Chinese Medical Association and Chinese College of Trauma Surgeons affiliated to Chinese Medical Doctor Association，in conjunction with national multidisciplinary experts，formulate the Chinese Consensus for Surgical Treatment of Traumatic Rib Fractures（2021）following the principle of evidence-based medicine，scientific nature and practicality. This expert consensus puts forward some clear，applicable，and graded recommendations from aspects of preoperative imaging evaluation，surgical indications，timing of surgery，surgical methods，rib fracture sites for surgical fixation，internal fixation methods and material selections，treatment of combined injuries in rib fractures，in order to provide references for surgical treatment of traumatic rib fractures.