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The tensile and compressive tests on woven carbon fiber epoxy resin composite specimens in different hygrothermal environments were carried out. The moisture absorption, tensile and compressive properties, fracture morphology and dynamic mechanical properties were analyzed. The influence of hygrothermal environments on tensile and compressive properties was investigated. The results show that the absorption process of carbon fiber epoxy composites satisfies Fick's law, and its saturated moisture absorption rate is about 0.86%. After moisture absorption, the surface of specimens becomes smooth, the phenomenon of few fibers pull-out and resin damage occurs, but no chemical reaction and no new substances is generated. After moisture absorption at 130℃, the retention rate of tensile properties is 96%, but the retention rate of compression properties is only 69%. The glass transition temperature of composite laminates after moisture absorption decreases by 33℃ compared with that in dry state.

The influence of thermal-oxidative aging on flexural property of carbon fiber bismaleimide resin composites was investigated via three point flexural test. The mass loss behavior, fracture morphology, dynamic mechanical property and IR spectrum of the composites were analyzed at different aging time. The results show that with the increase of aging time, the mass loss rate at 100℃ aging temperature gradually tends to stabilize and the mass loss rate at 180℃ aging temperature gradually increases. There is only physical aging at 100℃ aging temperature and no new substance is generated; but at the aging temperature 180℃, the chemical aging occurs and results in thermal aging and oxidation reactions, causing the degradation of matrix and interface properties. The influence of thermal-oxidative aging on flexural strength of composites is greater than flexural modulus.

The influence of water temperature on composite moisture absorption parameters was investigated in temperature-controlled water bath. Experiments of carbon fiber/bismaleimide resin composites immersed in water of 60℃, 70℃and 80℃ were developed respectively. According to the moisture content-time curves obtained from the experimental results, the diffusion coefficient and the balanced moisture content of the composites immersed in different water temperature could be calculated. What's more, the effect of water temperature on the diffusion coefficient and the balanced moisture content were discussed too. According to the Arrhenius equation and the law of Fick, a moisture absorption model was proposed to simulate the hygroscopic behaviour of the composite laminates immersed in different water temperature which can predict the absorption rate of water of the composites immersed in distilled water of 95℃ at any time precisely and can calculate how long it will take to reach the specific absorption rate.

Objective: To assess the impact of early enteral nutrition (EN) on the intestinal motility of patients after esophagectomy., Methods: Thirty-five consecutive patients undergoing esophagectomy for esophageal cancer by a single surgical team from the Peking University Cancer Hospital from June 2011 to July 2011 were enrolled. Patients were randomly divided into EN group (n=20) and parenteral nutrition group (control group, n=15) within 24 h after esophagectomy procedure. Bowel sound recovery time was monitored by auscultation, and the gastrointestinal tract symptoms were recorded., Results: Bowel sound recovery time was (45.1±20.3) h in the EN group, and was (56.7±17.0) h in the control group (P=0.082). Gastrointestinal symptoms such as nausea, abdominal distension, diarrhea occurred in 4 patients in EN group and 3 patients in control group and were alleviated by lowering infusion speed and more off-bed ambulation, and no significant difference was seen between the two groups (P=1.000)., Conclusions: Early enteral nutrition in the patients after esophagectomy is safe and feasible. Early enteral nutrition does not delayed bowel function recovery or increase gastrointestinal symptoms.

Objective: To summarize the surgical outcome of patients with small cell esophageal carcinoma(SCEC)., Methods: Clinical data of patients with esophageal carcinoma were retrospectively collected from March 2000 to March 2011 at the Thoracic Surgery Department of the Peking University Cancer Hospital. Data included tumor characteristics, staging, treatment, response, short-term outcome, and long-term survival., Results: A total of 546 patients with esophageal carcinoma were identified, among whom there were 15 patients with SCEC(2.7%). Fourteen cases received multimodality treatment based on operation and one underwent operation alone. Four patients had preoperative chemotherapy and 10 had postoperative chemotherapy. Four patients had postoperative radiation. After excluding one case of postoperative death within 3 months, the median overall survival was 14.3 months(range, 4 to 99 months), significantly worse than those with non-SCEC(42.2 months, P<0.05)., Conclusion: SCEC is rare and the outcomes are poor. It should be considered as a systematic disease.

Objective: To evaluate the long-term survival of multidisciplinary treatment based on thoracic surgery for cervical esophageal squamous cell carcinoma., Methods: The clinical characters and follow-up data of forty-one cervical esophageal cancer patients who accepted multidisciplinary treatment based on surgery with preservation of pharynx and larynx were retrospectively reviewed, and the long-term survival was compared with 480 non-cervical esophageal cancers who accepted surgery in the same period done by the same surgical team., Results: There were 28 males and 13 females with a mean age of 62 years old. In the cervical esophageal cancer group, 30 patients accepted neoadjuvant chemotherapy, 25 patients accepted adjuvant chemotherapy, and 21 patients accepted both. Six patients received postoperative radiation. Four patients underwent exploratory surgery alone, and 37 cases underwent radical surgery and cervical anastomosis. One case died during the perioperative period. The 1-, 3-, 5- and 8-year survival rates were 96.8%, 52.6%, 35.1%, and 35.1% in the 36 patients with cervical esophageal cancer who underwent radical surgery, and were 85.0%, 54.3%, 45.0%, and 36.7% respectively in the 457 non-cervical esophageal cancer patients. There was no significant difference between the cervical group and non-cervical group(P=0.91)., Conclusion: Cervical esophageal cancer should be treated in a multidisciplinary approach to obtain satisfactory long-term outcomes.

Objective: To explore the management strategies and outcome of treatment for multi-focal esophageal carcinoma., Methods: Twenty two patients with multi-focal esophageal carcinoma who underwent esophagectomy by a single surgeon team from March 2000 to March 2011 at the Beijing Cancer Hospital were reviewed retrospectively. The clinical and pathological characters were analyzed, and the outcome was compared with that of 471 patients with single esophageal carcinoma who received esophagectomy by the same surgeon team during the same period., Results: Eighteen out of 22 patients with multi-focal esophageal cancer underwent esophagectomy via transthoracic approach while 4 patients via transhiatal. Eight patients received neoadjuvant chemotherapy and 15 patients received adjuvant chemotherapy. Four hundred and seventy-one out of 471 patients with single esophageal cancer underwent esophagectomy via transthoracic approach while 60 patients via transhiatal. One hundred and fourty-eight patients received neoadjuvant chemotherapy and 267 patients received adjuvant chemotherapy. The 3-year survival of the 22 patients with multi-focal esophageal carcinoma was 41.9%, and the median survival time was 29.2 months. The 3-year survival of the 471 patients with single esophageal carcinoma was 54.7%, and the median survival time was 46.8 months. There was no significant difference in survival between the two groups(P=0.051)., Conclusions: The prognosis of patients with multi-focal occurrence esophageal carcinoma was poor. Extended esophageal resection may be beneficial to these patients with concurrent systemic chemotherapy.

Objective: To evaluate the long-term efficacy of transhiatal esophagectomy (THE) for esophageal carcinoma or esophagogastric junction cancer., Methods: Between March 2000 and December 2009, a total of 544 patients with either esophageal carcinoma or esophagogastric junction cancer underwent esophagectomy via THE (n=63) or other approaches (n=481) in Beijing cancer hospital institution. Procedures were performed by a single surgeon team. Long-term survival was compared between two groups., Results: The 1-year, 3-year, 5-year, and 8-year accumulative survival rates in THE group were 91.0%, 60.5%, 44.6%, and 44.6%, respectively, while those in non-THE group were 84.5%, 49.2%, 37.2%, and 28.7%, respectively. The THE group showed better long-term survival than the non-THE group, however the difference was not statistically significant., Conclusion: THE is a safe alternative for esophageal carcinoma and esophagogastric junction cancer.

Objective: To investigate the pathological feature of primary hepatic carcinoma and the clinical significance., Methods: From August 2000 to December 2007, there were 89 patients with cirrhosis and carcinoma of liver who accepted whole liver resection. The whole liver was cut into 10 mm slices to examine the tumor size, number, distribution, capsule, satellite nodes, portal vein tumor thrombi (PVTT). The invaded adjacent tissue and lymph nodes were recorded, the distance from satellite to major tumor was measured, then histological examinations were carried out, and the final diagnosis was made by pathologists., Results: The total of 89 cases included hepatocellular carcinoma in 86 cases and cholangiocarcinoma in 3 cases; 53 cases with multiple tumors and 36 cases with solitary tumor; complete capsule only in 14 cases, no obvious margin in 11 cases, 13 cases had a major tumor in the right lobe and a small tumor in the left lobe; 8 of 25 cases with gross invaded tissue were confirmed by histological examination, 7 of 16 cases with swollen lymph nodes were infiltrated by cancer cells. There were 47 cases with PVTT (47.2%) and 39 cases with satellite nodes (43.8%). PVTT and satellite nodes increased with the increase of sizes and the numbers of the tumors. The distance from satellite node to major tumor mostly were 0.5 - 3.0 cm., Conclusions: The whole explanted liver can completely reflect the characteristics of growth and infiltration of hepatic carcinoma. Attention must be paid to the small cancer lesions in another lobe, distal satellite nodes from major tumor, and tumor thrombi in a small branch of portal vein, which can not be found by imaging, and might influence the curative effectiveness after liver resection or transplantation.

Objective: To evaluate the clinical values of color Doppler ultrasound (BUS?) and magnetic resonance angiography (MRA) in diagnosis of the tumor emboli and thrombi in portal venous system., Methods: Examination of the portal venous system by BUS and MRA was conducted on 165 patients with undergoing liver transplantation because of cirrhosis or primary hepatic carcinoma before the operation. The extrahepatic portal vein was observed during operation and pathological examination was conducted after the operation. The results of BUS and MRA were compared as regards the sensitivity and specificity in discovering the tumor emboli and thrombi in portal venous system., Results: The overall sensitivity, specificity, and positive predictive rate of BUS for the portal vein embolus were 86.5%, 97.4%, and 85.3% respectively. The overall sensitivity, specificity, and positive predictive rate of MRA for the portal vein embolus were 90.5%, 99.3%, and 95.7% respectively. However the accuracy in diagnosing the nature of the portal venous embolus was less than 70% for these 2 methods., Conclusion: Non-invasive, both BUS and MRA help discover the portal vein embolus. However, false positivity and false negativity still exist. And both fail to diagnose the nature of the portal venous embolus.