BACKGROUND:Traditional studies on foot and ankle biomechanics have limitation. Ankle joint was complicated and had big range of motion, so it is difficult to establish finite element models and to analyze the type of fracture.
OBJECTIVE: To construct the finite element models of distal tibial fractures and analyze the stability.
METHODS: CT data of ankle were colected from a normal male volunteer and the three-dimensional reconstruction of volunteer was made by Mimics software, and the effectiveness was verified. The ratio of different joint involvement and height of fracture block were assumed with Solidwork software, and finite element models of distal tibial fractures were established. Fracture stability was analyzed by ANSYS software using finite element method.
RESULTS AND CONCLUSION:The distal tibia fracture model was consistent with the relevant literature data, and finite element analysis could be further conducted. The ratio of articular surface involved was positively associated with fragment height and fracture displacement, and negatively associated with fracture stability. These results indicate that the three-dimensional finite element models of distal tibial fractures were successfuly established. Fracture stability was associated with the ratio of articular surface involved and fragment height.

Objective To analyze the effect of different areas of paries medialis defect of femoral trochanter on the stability of fracture ends after percutaneous compression plating for femoral intertrochanteric fracture.Methods Thirteen preserved cadaveric specimens of adult femur were used in this experiment.The age of death ranged from 30 to 50 years.Oblique osteotomy was conducted under the same condition using a wire saw to create experimental models of fracture of Evans-Jensen type Ⅳ.The ratios of the area of paries medialis defect to the projected area of lesser trochanter in the specimens 1 to 13 were set respectively as 0,10.0％,14.5％,20.2％,23.4％,30.6％,45.8％,56.8％,76.8％,88.7％,99.8％,121.3％ and 149.4％.All the fractures were fixated by standard percutaneous compression plating.Cyclic load was applied on each specimen using Instron 2000 universal material tester.A vertical load of 600 N was applied for respectively 1,10,100 and 1,000 times to measure the displacements of proximal and distal fracture ends.Results When the ratio of the area of paries medialis defect to the projected area of lesser trochanter was 30.6％,the average displacements of the proximal and distal ends were 0.14 cm and 0.10 cm.When the ratio was 45.8％,the average displacement of the proximal end was 0.53 cm,278.6％ greater than that for 30.6％;the average displacement of the distal end was 0.41 cm,310.0％ greater than that for 30.6％.When the ratio was 149.4％,the average displacement of the proximal end was 0.93 cm,564.3％ greater than that for 30.6％;the average displacement of the distal end was 0.65 cm,550.0％ greater than that for 30.6％.Conclusions When the ratio of the area of paries medialis defect to the projected area of lesser trochanter reaches ＞ 45.8％,the area of paries medialis defect will have a significant effect on the stability of fracture ends after percutaneous compression plating for femoral intertrochanteric fracture.The displacement will increase linearly under the same compression with the increase in defect area.

Objective To establish a multiple regression equation of long delayed recall of the amnestic mild cognitive impairment,in order to predict the scores.Methods 248 old people were investigated by convenience sampling.Auditory verbal learning test (AVLT) was used to evaluate the ability of memory of the old people,and their general demographic data were collected.Multivariate linear regression analysis was conducted,the regression model was established and AVLT-long delayed recall scores (N5) to the predicted value got from the 3 times scores of study stage scores (N1,N2,N3) and short delayed recall (N4) of Auditory Verbal Learning Test were compared.Results The multiple linear regression equation between the variables was established.There was no significant difference between N5 and the predicted value.Conclusions N2,N3,N4 could be used to predict N5 during screening of amnestic mild cognitive impairment to make the screening process faster and briefer.When the score ≤4 points,the screening continues,if the score ＞5 points,the screening ceases in order to improve the efficiency of screening.

Objective To investigate the initial effect of LARS artificial ligaments arthroscopically in reconstruction of ipsilateral anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL).Methods A total of 21 patients (13 males and 8 females,at average age of 31.5 years) received ACL and PCL restoration using LARS artificial ligaments since June 2006.Preoperative MRI exactly confirmed them as ACL and PCL ruptures.Lysholm score on knee joint was (47.6 ±6.7) points.Surgery had reconstruction of PCL prior to ACL under arthroscope.Results All patients were followed up for average 42 months (range,36-49 months),which showed no infection,ligament rupture,ligament loosening,or other postoperative complications.At postoperative 3 years,Lysholm score was (90.8 ± 3.7) points and International Knee Documentation Committee (IKDC) score was normal in 14 patients,near normal in six,and abnormal in one,with excellent-good rate of 95％.Conclusions LARS artificial ligaments can attain anatomical reconstruction and stability of the knee joint in treatment of ACL and PCL ruptures.Meanwhile,arthroscopic surgery shows superiorities of micro-wound,rapid recovery and satisfactory curative effect.

Objective To investigate the microRNAs expression profile in human colorectal cancer with or without liver metastasis and try to screen miRNA associated with liver metastasis in colorectal cancer. Methods Twenty five surgical resected colorectal cancer specimens were collected and frozen in liquid nitrogen. Three without liver metastasis and three with liver metastasis were selected, from which total RNAs were isolated. The expressions of miRNAs in these two types of specimens were detected by illumine microRNA microarray, and the difference of miRNA expression was screened. The biochip results were verified with real-time RT-PCR in all colorectal caner specimens. Results The miRNA expression was significantly different in colorectal cancer with liver metastasis and without liver metastasis. Compared with colorectal cancer without liver metastasis, 28 miRNA expressions was different in colorectal cancer with liver metastasis, 4 up regulated and 24 down regulated. The quantity of miR-139-3p expression in colorectal cancer with liver metastasis was 1.75±0.40, up regulated compared with that incolorectal cancer without liver metastasis(0. 69 ±0.58,P＜0.05). The quantity of miR-19a expression in liver metastasis was 0. 39±0. 20, downregulated compare with no liver metastasis( 1.38 ± 0.98, P＜0. 05). The result of miRNA biochip was consistent with that of RT-PCR. Conclusion The difference of miRNA expression might relate to liver metastasis of colorectal cancer. The specific miRNAs expression profile might provide new target for diagnosis and treatment of colorectal cancer with liver metastasis.

In recent years, the detection rate of early gastric cancer in China has increased. Early gastric cancer has a good prognosis, and how to further improve the postoperative quality of life for patients has become an increasingly concerned problem in the treatment of early gastric cancer. Therefore, function preserving gastrectomy has emerged. Function preserving gastrectomy aims to reduce the resection scope and preserve part of the gastric function on the premise of radical tumor resection. As a representative of function preserving gastrectomy, pylorus-preserving gastrec-tomy is suitable for early gastric cancer in middle segment. Compared with distal gastrectomy, laparoscopic pylorus-preserving gastrectomy not only has the advantage of less trauma, but also can reduce the incidence of postoperative dumping syndrome, bile reflux gastritis and gallstones, and improve postoperative nutritional status. However, the practice of pylorus-preserving gastrectomy is still in controversial. Based on the new Japanese guidelines for the treatment of gastric cancer, and combined with the latest domestic and foreign research trends and relevant evidence-based medicine basis, the authors review the definition and indications, safety, advantages, technical points, digestive tract reconstruction methods, postoperative complications and other aspects of laparoscopic pylorus-preserving gastrectomy.

In the past few years, there has seen an increase in the detection rate of early upper gastric cancer. Early upper gastric cancer is of good prognosis. How to further enhance the postoperative quality of life of patients has increasingly become an issue of concern. This has naturally given rise to function-preserving proximal gastrectomy. However, due to its damage to the original structure of cardia and its vicinity, proximal gastrectomy is prone to postoperative reflux. To prevent postoperative reflux, various ways of digestive tract reconstruction have emerged one after another, but the optimal way thereof remains controversial. Therefore, reducing postoperative reflux through an appropriate way of digestive tract reconstruction has been taken as a focus of proximal gastrectomy. Esophagogastric anastomosis with seromuscular flap technique, as a way of digestive tract reconstruction, builds an "artificial cardia" on the basis of guarantee of normal entry of food into the digestive tract, and functions against postoperative reflux. For its good anti-reflux effect, eso-phagogastric anastomosis with seromuscular flap technique has gradually become a research focus. On top of the latest research progress at home and abroad and relevant evidence-based medicine, the authors provide on the principles, key points, improvement, postoperative status, and applica-tion of esophagogastric anastomosis with seromuscular flap technique in laparoscopic proximal gastrectomy.

Objective:To intestigate the clinical efficacy between modified Overlap anastomosis and traditional auxiliary incision anastomosis in laparoscopic total gastrectomy.Methods:The retrospective cohort study was conducted. The clinicopathological data of 115 patients with gastric cancer who were admitted to the Second Affiliated Hospital of Fujian Medical University from January 2016 to December 2018 were collected. There were 62 males and 53 females, aged from 27 to 83 years, with a median age of 62 years. Of 115 patients, 51 patients undergoing totally laparoscopic total gastrectomy with modified Overlap anastomosis using linear stapler were divided into modified Overlap group and 64 patients undergoing laparoscopic assisted total gastrectomy with traditional auxiliary incision anastomosis using circular stapler were divided into traditional assisted group. Observation indicators: (1) surgical situations; (2) postoperative situations; (3) anastomotic complications; (4) follow-up. Follow-up using outpatient examination or telephone interview was conducted to detected tumor recurrence and survival of patients up to December 2019. Measurement data with normal distribution were represented as Mean± SD, and comparison between groups was analyzed using the t test. Count data were represented as absolute numbers or percentages, and comparison between groups was analyzed using the chi-square test or Fisher exact probability. Comparison of ranked data was analyzed using the rank sum test. Results:(1) Surgical situations: the operation time, time of esophagojejunostomy, volume of intraoperative blood loss, the number of lymph node dissected, length of proximal incisional margin and length of auxiliary incision of the modified Overlap group were (234.0±11.0)minutes, (29.4±2.1)minutes, (53±14)mL, 42±13, (2.0±0.3)cm and (5.1±0.4)cm, respectively. The above indicators of the traditional assisted group were (231.0±11.0)minutes, (29.2±2.2)minutes, (50±13)mL, 40±10, (2.2±0.4)cm and (8.2±0.4)cm, respectively. There was significant difference in the length of auxiliary incision between the two groups ( t=-43.098, P<0.05), and there was no significant difference in the operation time, time of esophagojejunostomy, volume of intraoperative blood loss, the number of lymph node dissected, length of proximal incisional margin between the two groups ( t=1.168, 0.460, 0.990, 1.127, -1.926, P>0.05). (2) Postoperative situations: cases with mild, moderate, severe pain (postoperative pain degree), time to first flatus, time to initial fluid diet intake, duration of postoperative hospital stay of the modified Overlap group were 40, 9, 2, (2.9±1.0)days, (4.8±2.2)days, (11.7±2.8)days, respectively. The above indicators of the traditional assisted group were 31, 27, 6, (3.9±1.4)days, (6.5±2.5)days, (13.0±3.1)days, respectively. There were significant differences in the above indicators between the two groups ( Z=-3.217, t= -4.344, -3.888, -2.261, P<0.05). (3) Anastomotic complications: cases with anastomotic leakage, cases with anastomotic bleeding, cases with anastomotic stenosis of the modified Overlap group were 1, 1, 0, respectively. The above indicators of the traditional assisted group were all 1. There was no significant difference in the above indicators between the two groups ( P>0.05). Cases with anastomotic leakage were cured after the treatment of enteral nutritional support through nasogastric catheterization, which were confirmed by gastroenterography. Cases with anastomotic bleeding were improved by active hemostatic therapy. Cases with anastomotic stenosis were improved after the symptomatic treatment of anti-inflammatory and anti-swelling. (4) Follow-up: 109 of the 115 patients were followed up. Forty-eight of 51 patients in the modified Overlap group were followed up for 15.0-45.0 months, with a median follow-up time of 33.5 months. Sixty-one of 64 patients in the traditional assisted group were followed up for 16.0-46.0 months, with a median follow-up time of 27.0 months. There was no tumor recurrence in the modified Overlap group. One patient in the traditional assisted group had tumor recurrence with liver metastasis and survived with tumor. There was no significant difference in tumor recurrence rate between the two groups ( P>0.05). There was no patient died during the follow-up. Conclusion:Compared with traditional auxiliary incision anastomosis, patients undergoing total laparoscopic total gastrectomy with modified Overlap anastomosis have small incision, good postoperative recovery.

Objective:To investigate the clinical efficacy of laparoscopic-assisted inters-phincteric resection (ISR) with different surgical approaches for low rectal cancer.Methods:The retrospective cohort study was conducted. The clinicopathological data of 90 patients with low rectal cancer who were admitted to the Second Affiliated Hospital of Fujian Medical University from January 2016 to December 2020 were collected. There were 58 males and 32 females, aged (60±9)years. Of 90 patients, 60 cases underwent laparoscopic assisted ISR with transpelvic approach, 30 cases underwent laparoscopic assisted ISR with transabdominal and transanal mixed approach. Observation indicators: (1) clinicopathological characteristics of patients with transpelvic approach and mixed approach; (2) intraoperative and postoperative conditions of patients with transpelvic approach and mixed approach; (3) postoperative complications of patients with transpelvic approach and mixed approach; (4) follow-up. Follow-up was conducted by telephone interview and outpatient examination once every 3 months within postoperative 3 years, once every six months in the postoperative 3 to 5 years and once a year after postoperative 5 years to detect tumor recurrence and metastasis, and survival of patients.Follow-up was up to March 2021 or patient death. Measurement data with normal distribution were represented as Mean± SD, and the t test was used for comparison between groups. Measurement data with skewed distribution were expressed as M(range), and comparison between groups was conducted using the non-parametric Mann-Whitney U test. Count data were expressed as absolute numbers or percentages, and comparison between groups was performed using the chi-square test or Fisher exact probability. Comparison of ordinal data was analyzed by the non-parametric rank sum test. Kaplan-Meier method was used to draw survival curves and calculate survival rates, and survival analysis was performed by the Log-Rank test. Results:(1) Clinicopathological characteristics of patients with transpelvic approach and mixed approach. The sex (males, females), distance from the distal margin of tumor to anal margin were 34, 26, (4.5±0.5)cm for patients with transpelvic approach, versus 24, 6, (3.5±0.5)cm for patients with mixed approach, respectively, showing significant differences between them ( χ2=4.75, t=8.35, P<0.05). (2) Intraoperative and postoperative conditions of patients with transpelvic approach and mixed approach. The operation time, volume of intraoperative blood loss, distance from the postoperative anastomosis to anal margin were (187±9)minutes, 50(range, 20?200)mL, (3.4±0.7)cm for patients with transpelvic approach, versus (256±12)minuets, 100(range, 20?200)mL, (2.6±0.7)cm for patients with mixed approach, showing significant differences between them ( t=?26.99, Z=?2.48, t=4.67, P<0.05). None of the 90 patients had a positive distal margin. The stoma reversal rates of patients with transpelvic and mixed approach were 93.3%(56/60) and 90.0%(27/30), respectively. Of the 60 patients with transpelvic approach, 3 cases had no stoma reversal due to anastomotic complications, and 1 case was not yet to the reversal time. Of the 30 patients with mixed approach, 2 cases had no stoma reversal due to anastomotic complications, and 1 case was not yet to the reversal time. The 1-, 3-month Wexner scores after stoma reversal were 15(range, 12?17), 12(range, 10?14) for patients with transpelvic approach, versus 16(range, 14?18), 14(range, 12?16) for patients with mixed approach, showing significant differences between them ( Z=?4.97, ?5.49, P<0.05). The 6-month Wexner score after stoma reversal was 10(range, 9?12) for patients with transpelvic approach, versus 11(range, 8?12) for patients with mixed approach, showing no significant difference between them ( Z=?1.59, P>0.05). (3) Postoperative complications of patients with transpelvic approach and mixed approach. The complications occurred to 16 patients with transpelvic approach and 9 patients with mixed approach, respectively, showing no significant difference between them ( χ2=0.11, P>0.05). Cases with postoperative anastomotic fistula, cases with anastomotic bleeding, cases with anastomotic stenosis, cases with intestinal obstruction, cases with incision infection, cases with urinary retention, cases with pelvic infection, cases with pulmonary infection, cases with incisional hernia, cases with chylous fistula, cases with abdominal and pelvic abscess were 5, 2, 1, 7, 0, 1, 5, 3, 1, 1, 1 for patients with transpelvic approach, versus 6, 3, 2, 2, 2, 1, 2, 3, 1, 1, 1 for patients with mixed approach, showing no significant difference between them ( P>0.05). The same patient could have multiple postoperative complications. (4) Follow-up. All the 90 patients were followed up for 27(range, 6?62)months. The follow-up time of 60 patients with transpelvic approach was 27(range, 8?62)months. The follow-up time of 30 patients with mixed approach was 28(range, 6?53)months. Of the 60 patients with transpelvic approach, 3 cases had local recurrence, 4 cases had liver metastasis, 3 cases had lung metastasis, and all of them survived with tumor. Of the 30 patients with mixed approach, 1 case had local recurrence, 2 cases had liver metastasis, 1 case had lung metastasis, and all of them survived with tumor. There was no death. The 3-year disease-free survival rates of patients with transpelvic approach and mixed approach were 84.7% and 87.9%, respectively, showing no significant difference between them ( χ2=0.39, P>0.05). Conclusions:Lapa-roscopic assisted ISR via transpelvic approach or mixed approach for low rectal cancer are safe and feasible. Compared with transanal mixed approach, the transpelvic approach of laparoscopic-assisted ISR has shorter operation time, less volume of intraoperative blood loss and longer distance from the postoperative anastomosis to anal margin.

African swine fever virus(ASFV)I177L gene deletion vaccine is one of the key directions of African swine fever(ASF)live attenuated vaccine research and development.In order to effec-tively distinguish between the wild-type ASFV strain and the I177L gene-deleted strain,specific primers and probes were designed based on ASFV B646L and I177L genes,respectively.After screening and optimization,a duplex real-time PCR method was developed that can simultaneously detect these two genes.The results showed that ASFV B646L and I177L genes were detected spe-cifically and simultaneously by the method developed without cross-reactions with porcine circovir-us type 2,Seneca virus A,classical swine fever virus,foot-and-mouth disease virus,porcine respira-tory and reproductive syndrome virus.The detection limits of the duplex real-time PCR for recom-binant plasmids pUC57-B646L and pUC57-I177L were 1×103 copies/mL.The intra-and inter-as-say coefficients of variation were less than 4％,respectively.Detection of 122 pork and pork prod-ucts using the duplex real-time PCR developed and the real-time PCR recommended by WOAH showed that the coincidence rates of the two methods for B646L gene detection was 100％with two amplification curves appeared in the positive results of the established methods.The method established in this study can be used for the detection of ASFV I177L gene deletion strains,which provides technical support for ASF surveillance and epidemiological investigation.