Fracture Classification and Injury Segment Analysis of Tibiofibula and Ankle in Half-Squat Parachuting Landing / 医用生物力学

Objective To make classification and segment measurement for the cases with tibiofibular and ankle fractures in parachuting landing, and investigate main classification types of parachuting fractures and fracture segments of high risk.Methods A total of 56 fracture cases in parachuting landing were collected, and the tibiofibula and ankle fractures were classified according to AO-OTA or Lauge-Hansen classification standards respectively based on their digital X-ray images. The medium plane between talus and tibia joint planes in ankle joint was defined as the reference plane. The highest and lowest injury points of tibia and fibula were marked respectively, and the fracture segment was defined between the highest and lowest point for statistical analysis.Results For tibiofibular and ankle fracture cases in parachuting landing, fracture at both tibia and fibula accounted for 80.4%. The major classification of tibiofibula fracture was 42-D/5.2 (45.8%) and 42-D/5.1 (16.7%). The major classification for ankle fracture was pronation-external rotation (PER, 59.4%) and supination-external rotation (SER, 37.5%). When tibiofibular and ankle fracture cases in parachuting landing occurred, the fracture segment of the tibia was mainly from 57 to 143 mm above the reference plane and from 6 mm below the reference plane to 24 mm above the reference plane, while the fracture segment of the fibula was 4-45 mm and 74-83 mm above the reference plane. Injury risks of all above segments were higher than 50%.Conclusions For protection of lower limbs in parachuting landing, the fracture at both tibia and fibula should be highly noticed. The ankle motion of PER and SER should be especially restricted in parachuting ankle protection.

Risk factors for pancreatic fistula after laparoscopic pancreaticoduodenectomy / 中华普通外科杂志

Objective:To investigate the preoperative and intraoperative risk factors of clinical pancreatic fistula after laparoscopic pancreaticoduodenectomy (LPD).Methods:Clinical data of 100 patients undergoing LPD at the Second Department of Hepatobiliary and Pancreatic Surgery of the First Hospital of Jilin University from Jan 2019 to May 2019 were studied.Results:The total incidence of pancreatic fistula was 8%, and the incidence of clinical pancreatic fistula (grade B, C) was 6%. Univariate analysis found that gender (male), preoperative pancreatic plain CT value <33HU, soft texture of the pancreas, long operation time, alcoholic consuming history may be risk factors for pancreatic fistula after LPD( P<0.05), and further multivariate analysis found gender (male), preoperative pancreatic plain CT value <33 HU, soft texture of the pancreas were independent risk factors for clinical pancreatic fistula after LPD( P<0.05). Conclusions:Male patients, preoperative pancreatic plain CT value <33HU, soft texture of the pancreas were respectively independent risk factors predicting post-LPD clinical pancreatic fistula.

Clinical effect of the enhanced recovery after surgery strategy for pancreaticoduodenectomy / 临床肝胆病杂志

ObjectiveTo investigate the clinical effect and safety of the enhanced recovery after surgery (ERAS) strategy in the perioperative period of pancreaticoduodenectomy (PD). MethodsA retrospective analysis was performed for the clinical data of 100 patients who underwent PD in The First Hospital of Jilin University from August 2012 to July 2016. The patients were divided into ERAS group and control group according to the management mode during the perioperative period, with 50 patients in each group. The patients in the control group were given routine management, and those in the ERAS group were given ERAS management. The two groups were compared in terms of mortality rate, incidence rate of complications, time of operation, diet, intestinal function, length of postoperative hospital stay, hospital costs, secondary surgical intervention, and readmission rate. The t-test was used for comparison of continuous data between two groups, and the chi-square test or the Fisher’s exact test was used for comparison of categorical data between two groups. ResultsTwo patients in the control group and one in the ERAS group died after surgery. There were no significant differences in mortality, reoperation, and readmission rates between the two groups (all P＞0.05). Compared with the control group, the ERAS group had a significantly lower incidence rate of complications (31.0% vs 56.3%, χ2=5.84, P=0.016) and significantly shorter time to first flatus, time to diet, time to ambulation, and time to removal of drainage tube and other tubes (all P＜0.001). There were significant differences between the ERAS group and the control group in length of hospital stay (14.3±1.2 d vs 18.5±1.8 d, t=13.73, P＜0.001) and total hospital costs ［10.7±1.4 ten thousand yuan vs 13.2±4.1 ten thousand yuan, t=4.08, P＜0.001］. ConclusionThe ERAS strategy is safe and effective in the perioperative period of PD and can significantly reduce hospital costs, shorten the length of hospital stay, standardize perioperative management, diminish clinical variability, and thus help patients to achieve enhanced recovery. Therefore, it holds promise for clinical application.

Analysis of epileptic seizure detection method based on improved genetic algorithm optimization back propagation neural network / 生物医学工程学杂志

In order to improve the accuracy and efficiency of automatic seizure detection, the paper proposes a method based on improved genetic algorithm optimization back propagation (IGA-BP) neural network for epilepsy diagnosis, and uses the method to achieve detection of clinical epilepsy rapidly and effectively. Firstly, the method extracted the linear and nonlinear features of the epileptic electroencephalogram (EEG) signals and used a Gaussian mixture model (GMM) to perform cluster analysis on EEG features. Next, expectation maximization (EM) algorithm was used to estimate GMM parameters to calculate the optimal parameters for the selection operator of genetic algorithm (GA). The initial weights and thresholds of the BP neural network were obtained through using the improved genetic algorithm. Finally, the optimized BP neural network is used for the classification of the epileptic EEG signals to detect the epileptic seizure automatically. Compared with the traditional genetic algorithm optimization back propagation (GA-BP), the IGA-BP neural network can improve the population convergence rate and reduce the classification error. In the process of automatic detection of epilepsy, the method improves the detection accuracy in the automatic detection of epilepsy disorders and reduced inspection time. It has important application value in the clinical diagnosis and treatment of epilepsy.

Application of Hong's pancreaticojejunostomy in laparoscopic pancreaticoduodenectomy on 184 patients / 中华肝胆外科杂志

Objective@#To evaluate the efficacy and safety of Hong's pancreaticojejunostomy in laparoscopic pancreaticoduodenectomy.@*Methods@#A retrospective analysis was carried out on 184 patients who underwent laparoscopic pancreaticoduodenectomy using Hong's pancreaticojejunostomy (the Hong’s pancreaticojejunostomy group) compared with 100 patients who underwent laparoscopic pancreaticoduodenectomy using traditional pancreaticojejunostomy (the traditional pancreaticojejunostomy group) at Department of Second Hepatobiliary and Pancreatic Surgery, the First Bethune Hospital of Jilin University, from April 2016 to December 2018. The differences between the two anastomotic methods in operation time, pancreaticojejunostomy time, intraoperative blood loss, postoperative hospital stay, postoperative complications, and incidences of pancreatic fistula were compared.@*Results@#The operation time, pancreaticojejunostomy time and intraoperative blood loss of the Hong's pancreaticojejunostomy group were significantly less than the traditional pancreaticojejunostomy group [(278.2±49.3) min vs. (337.3±67.4) min, (33.7±6.6) min vs. (46.8±8.5) min, (123.1±44.7) ml vs. (203.8±138.6) ml], respectively, (all P<0.05). There were no significant differences in postoperative hospital stay and pancreatic fistula rates between the two groups (all P>0.05).@*Conclusions@#Hong's pancreaticojejunostomy was safe, rapid and effective compared with traditional pancreaticojejunostomy. It did not increase the incidence of pancreatic fistula.

Differences of Neck Injury Risks for Different Dummies During Arrested Landing / 医用生物力学

Objective To compare the differences of neck injury risks for different mummies during arrested landing on naval vessels. Methods Based on the established dynamic model of dummy-belt-seat systems and mechanical model of head-neck, with the acceleration curve at seat base during typical arrested landing reported in the literature as the input, numerical simulation was conducted to test the validity of the model, and the axial force, shear force， bending moment of typical joints in dummy neck during arrested landing were obtained. Results The injury index Nkm of 95 percentile dummy was higher than that of 5 percentile dummy. The injury index Nij of the dummy’s upper and lower cervical spine was smaller than 0.2, meanwhile the Nkm was around 0.65. Conclusions During arrested landing, human neck was much easier to get hurt due to the shear force. The research findings can provide data support for evaluating neck injury risks of pilots with different sizes during typical arrested landing process.

Diagnosis and surgical therapy for residual gallbladder in 52 cases / 中华普通外科杂志

Objective To evaluate the diagnosis and treatment of residual gallbladder.Methods The diagnosis of residual gallbladder depends on a history of previous cholecystectomy and postoperative existent symptoms suggesting cholecystitis.In this series the diagnosis was finally established by ultrasonography and laparotomy in 52 cases.Results Ten cases received laparoscopic residual cholecystectomy,32 cases underwent residual cholecystectomy,7 cases did residual cholecystectomy plus common bile duct exploration,1 case was treated with residual cholecystectomy,common bile duct exploration and left lateral lobe hepatectomy,1 case with residual cholecystectomy,common bile duct exploration,cholangioenterostomy,1 case by radical resection of residual gallbladder cancer.Conclusions Residual gallbladder is a secondary disease,diagnosis is not difficult,surgery has certain difficulty,the application of intraoperative ultrasound and choledochoscope has great value.

Working conditions of bipolar radiofrequency on human articular cartilage repair following thermal injury during arthroscopy / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>The thermal injury during bipolar radiofrequercy results in chondrocyte death that limits cartilage repair. The purpose was to determine the effects of various factors of bipolar radiofrequency on human articular cartilage after thermal injury, offering suitable working conditions for bipolar radiofrequency during arthroscopy.</p><p><b>METHODS</b>Osteochondral explants from 28 patients undergoing total knee arthroplasty (TKA) in Department of Orthopaedic, Peking University Reople's Hospital from October 2013 to May 2014, were harvested and treated using bipolar radiofrequency in a light contact mode under the following conditions: various power setting of levels 2, 4 and 6; different durations of 2 seconds, 5 seconds and 10 seconds; irrigation with fluids of different temperatures of 4°C, 22°C, and 37°C; two different bipolar radiofrequency probes ArthroCare TriStar 50 and Paragon T2. The percentage of cell death and depth of cell death were quantified with laser confocal microscopy. The content of proteoglycan elution at different temperatures was determined by spectrophotometer at 530 nm.</p><p><b>RESULTS</b>Chondrocyte mortality during the treatment time of 2 seconds and power setting of level 2 was significantly lower than that with long duration or in higher level groups (time: P = 0.001; power: P = 0.001). The percentage of cell death after thermal injury was gradually reduced by increasing the temperature of the irrigation solutions (P = 0.003), the depth of dead chondrocytes in the 37°C solution group was significantly less than those in the 4°C and 22°C groups (P = 0.001). The proteoglycan elution was also gradually reduced by increasing the temperature (P = 0.004). Compared with the ArthroCare TriStar 50 group, the percentage of cell death in the Paragon T2 group was significantly decreased (P = 0.046).</p><p><b>CONCLUSIONS</b>Thermal chondroplasty with bipolar radiofrequency resulted in defined margins of chondrocyte death under controlled conditions. The least cartilage damage during thermal chondroplasty could be achieved with lower power, shorter duration, suitable temperature of irrigation solutions and chondroprotective probes. The recommendations for the use of bipolar radiofrequency to minimize cartilage damage could be achieved with a power setting of level 2, treatment duration of 2 seconds, suitable fluid temperature (closer to body temperature of 37°C) and chondroprotective Paragon T2 probes.</p>

The effect of two different preoperative biliary drainages on malignant obstructive jaundice complicated with acute cholangitis / 中华普通外科杂志

Objective To evaluate effects of two different preoperative biliary drainages on patients of malignant obstructive jaundice complicated with acute cholangitis.Methods Retrospective analysis was made on effects of two preoperative biliary drainages of ultrasound-guided percutaneous transhepatic cholangial drainage (PTCD) and endoscopic nasobiliary drainage (ENBD) in cases of malignant obstructive jaundice complicated with acute cholangitis.Results Days of preoperative drainage(t =3.217,P ＜ 0.05) and declines of bilirubin level after drainage (t =3.178,P ＜ 0.05) were significantly better in ENBD group (26 cases) than PTCD group (22 cases).There were no significant differences between two groups in operation time length and intraoperative blood loss after drainage.However,postoperative hospital stay (t =2.542,P ＜ 0.05) and overall stay (t =3.172,P ＜ 0.05) were significantly shorter in ENBD group compared with PTCD group.Conclusions When preoperative biliary drainage is indicated in the cases of malignant jaundice before radical surgery,ENBD should be the first choice over DTCD.

Research, design and application of model NSE-1 neck muscle training machine for pilots / 生物医学工程学杂志

Pain in the cervical region of air force pilots, who are exposed to high G-forces, is a specifically occupational health problem. To minimize neck problems, the cervical muscles need specific strength exercise. It is important that the training for the neck must be carried out with optimal resistance in exercises. The model NSE-1 neck training machine for pilots was designed for neck strengthening exercises under safe and effective conditions. In order to realize the functions of changeable velocity and resistant (CVR) training and neck isometric contractive exercises, the techniques of adaptive hydraulics, sensor, optic and auditory biological feedback, and signal processing were applied to this machine. The training system mainly consists of mechanical parts (including the chair of flexion and extension, the chair of right and left lateral flexion, the components of hydraulics and torque transformer, etc.), and the software of signal processing and biological feedback. Eleven volunteers were selected for the experiments of neck isometric contractive exercises, three times a week for 6 weeks, where CVR training (flexion, extension, right, left lateral flexion) one time a week. The increase in relative strength of the neck (flexion, extension, left and right lateral flexion) was 70.8%, 83.7%, 78.6% and 75.2%, respectively after training. Results show that the strength of the neck can be increased safely, effectively and rapidly with NSE-1 neck training machine to perform neck training.

Feasibility of fluoroelastomer-246B as the substitute of bile duct / 中国组织工程研究

BACKGROUND: Fluoroelastomer-246B has better histocompatibility than polyethylene and polypropylene, which is the same as expanded polytetrafiuoroethylene (ePTFE). Besides, fluoroelastomer-246B has better rigidity than ePTFE, so it is hard to deform.OBJECTIVE: To investigate the feasibility of fluoroelastomer-246B as a human implant in vivo and a substitute of human bile duct by the test of bile soak, routine sterilized method, and implantation into rat abdominal cavity.DESIGN: A controlled observation.SETTING: First Hospital of Jilin University & Key Laboratory of Education Ministry for Supramolecular Structure and Material of Jilin University.MATERIALS: This study was performed at the Key Laboratory of Education Ministry for Supramolecular Structure and Material of Jilin University from June 2006 to March 2007. A total of 35 male Wistar rats of clean grade, aged 4-5 weeks,weighing 140-160 g, were provided by Laboratory Animal Center, School of Basic Medical Sciences, Jilin University [Permission No. SCXK (Ji) 2003-0001]. Prior to surgery, the Wistar rats were fasted for 5 hours, but they were allowed to access to water freely. The main materials used in the present study were as follows: fluoroelastomer-246B (Yangzhong Municipal Rubber & Plastics Plant, China), ePTFE(Shanghai Suo-Kang Medical Implants Co.,Ltd., China).METHODS: Rectangular fluoroelastomer-246B thin slices (50 mm×10 mm×0.5 mm) made were placed in a beaker filled with fresh bile, and preserved in a 37 ℃ thermostat container. The tensile strength, thermal decomposition temperature and glass transition temperature of fluoroelastomer-246B were tested after 30 days, and the results were compared to those before soaking to investigate whether the physical-chemical properties of fluoroelastomer-246B slices would change after soaking in the bile environment for a long time. The rectangular fluoroelastomer-246B thin slices made as above were sterilized by boiling method, formaldehyde vapors fumigating method, and formaldehyde fluid soaking method. The indices mentioned above were measured, and the data were compared to those before sterilizing to identify whether fluoroelastomer-246B could be used after sterilizing. The same-size slice of fluoroelastomer-246B,ePTFE, polypropylene and polyethylene was separately implanted into rat abdominal cavity. The slices were taken out after 30 days, and the pathological sections of surrounding tissues were made to observe whether allergic response and/or inflammatory reactions existed.MAIN OUTCOME MEASURES: After fluoroelastomer-246B thin slices were soaked in bile for 30 days, their tensile strength, thermal decomposition temperature and glass transition temperature were tested, and the results were compared to those before soaking. After fluoroelastomer-246B thin slices were sterilized by boiling method, formaldehyde vapors fumigating method, and formaldehyde fluid soaking method, the indices mentioned above were measured, and the data were compared to those before sterilizing. The numbers of cells with allergic response and cells with inflammatory reaction were counted.RESULTS: After soaking in the fresh bile for 30 days, the tensile strength, thermal decomposition temperature and glass transition temperature of fluoroelastomer-246B changed slightly compared to before soaking (P＞0.05).Fluoroelastomer-246B could well antagonize mechanical stress after bile soaking and sterilizing. Under going sterilizing by boiling method, formaldehyde vapors fumigating method and formaldehyde fluid soaking method separately, the tensile strength, thermal decomposition temperature and glass transition temperature of fluoroelastomer-246B had no marked changes (P＞0.05). No noticeable allergic response was observed after fluoroelastomer-246B was implanted into rat abdominal cavity, whereas slight inflammatory reaction was detected, which was similar to ePTFE (P＞0.05).CONCLUSION: The primary physical-chemical properties of fluoroelastomer-246B do not change after soaking in bile for 30 days. Fluoroelastomer-246B can well antagonize mechanical stress and be used after sterilizing without metaphysis or allergic response. Therefore, fluoroelastomer-246B can be used as a substitute of bile duct.

Design and development of artificial substitute for bile duct / 中国组织工程研究

BACKGROUND:The operation of bile duet has always been the most difficult part in the general surgery.The Patients have a high morbidity of the post-operative complications,such as bile duct stenosis,repeated biliary tract infection,and even biliary hepatocirrhosis.Therefore.we are seeking for some kind of artificial bile dlIct to take the place of the damaged one.and then solve the problem in bile duct's repair and reconstruction.OBJECTIVE:This paper reviewed the Iong-term plenty of related studies and litcratures.and then summarized the latest progress of the design and improvement of artificial bile duct.So we could design the optimum artificial bile duct.RETIUEVAL STRATEGY:A computer-based online search of PubMed database (http://www.pubmed.gov/)was undertaken to identify articles about artificial bile duct published in English from January 1959 to December 2007 with keyword of"artificial bile duct,stem cell,tissue engineering".Meanwhile,Chinese articles about artificial bile duct published from January 1994 to October 2007 were retrieved in China National Knowledge Infrastructure(CNKI,http://www.cnki.net),the keyword was"artificial bile duct,stem cell,tissue engineering"in Chinese.Inclusion criteria:①laboratorial and clinical researches about artificial bile duct;② clinical researches about the stem cells;③researches about tissue engineering and biocompatible materials.Exclusion criteria:repeated study.Initial reading these literatures and finding the full text,37feferences were included from the gleaning 414 literatures.LITERATURE EVALUATION:A total of 37 articles were involved.ineluding 10 about background.5 about autotransplant,5 about stem cell technique,2 about nanotechnology,1 about structure of mechanical bile duct,2 about macromolecular materials.and 12 about the latest progress.DATA SYNTHESIS:To analyze and sort out these literatures.the artificial bile duct from biocompatible materials and biomedical engineering is analyzed.The developments in autotransplantation,mechanical structure,nanotechnology,stem cell technique and tissue-engineered macromolecule material have been retained.So far,the tissue-engineered macromolecule material is the best one.Further study aiming at the better artificial bile duct is needed.CONCLUSION:There have been great progresses in research of artificial bile duct,however,there is no significant achievement because of the inextricable shortcomings and limits in autotransplantation,mechanical structure,nanotechnology and stem cell teehnique.Therefore.the tissue-engineered macromolecule material has become the best material for artificial bile duct.

Biological effect of artificial bile duct combined with bionic valve made by fluoroelastomers-246B following implantation in dogs / 中国组织工程研究

0.05). At day 30 after operation,half-pipe blockage occurred,and some yellow-green sediments were observed on the pipe wall in the straight tube group; a few of yellow-green sediments were found at top of wall,and some white floc sediments were observed in lumen but nothing was observed on valve in the venous valve tube group; a few of yellow-green sediments were found on pipe wall near the living valve,and some white floc sediments were observed in bile in the living valve tube group. At day 30 after operation,epithelium of mucous membrane was not intact,and gland proliferated lightly in the straight tube group; epithelium of mucous membrane was generally intact,and proliferation of gland was not found in the venous valve tube group; epithelium of mucous membrane was exactly intact,and glandular epithelial cells were not heteromorphism in the living valve tube group. CONCLUSION:The artificial bile ducts with a valve structure and living value structure has a good patency and plays an effective role of anti-reflux after a short-term observation,suggesting that a valve structure acts as a similar function to Oddis sphincter.