熔体过热和脉冲磁场协同处理对Mn_(5)Si_(3)增强Cu-35Zn-3Al合金显微组织、力学和耐磨性能的影响

研究熔体过热和脉冲磁场协同处理对Mn_(5)Si_(3)增强Cu-35Zn-3Al合金显微组织、力学和耐磨性能的影响。研究结果表明,协同处理促进了熔体中的溶质迁移以及Mn_(5)Si_(3)晶体生长的吸附动力学,抑制了六棱柱形貌Mn_(5)Si_(3)颗粒上孔洞的形成。协同处理后热锻态合金的抗拉强度和伸长率分别提高了9.0%和66.5%,这是由于拉伸变形过程中不含孔洞的Mn_(5)Si_(3)颗粒断裂强度提高,产生的应力集中减小,因此失效方式由脆性解理断裂转变为从基体中拔出,颗粒和基体间的载荷传递作用增强。在承受摩擦时,协同处理后合金的磨损亚表层中Mn_(5)Si_(3)颗粒不易发生剪切断裂,抑制了裂纹扩展和材料剥落,因而产生的剥层磨损减小,合金耐磨性显著提高。

Preservation of left colic artery in laparoscopic colorectal operation: The benefit challenge

BACKGROUND During laparoscopic resection for colorectal cancer,there is controversy regarding whether the left colic artery(LCA)should be preserved at its origin.AIM To investigate the prognostic significance of preservation of the LCA in colorectal cancer surgery.METHODS Patients were divided into two groups.The high ligation(H-L)technique(refers to ligation performed 1 cm from the beginning of the inferior mesenteric artery)group consisted of 46 patients,and the low ligation(L-L)technique(refers to ligation performed below the initiation of the LCA)group consisted of 148 patients.Operative time,blood loss,lymph nodes with tumor invasion,postoperative complications and recovery time,recurrence rate,and 5-year survival rate were compared between the two groups.RESULTS The average number of lymph nodes detected in postoperative pathological specimens was 17.4/person in the H-L group and 15.9/person in the L-L group.There were 20 patients(43%)with positive lymph nodes(lymph node metastasis)in the H-L group and 60 patients(41%)in the L-L group.No statistical differences were found between the groups.Complications occurred in 12 cases(26%)in the H-L group and in 26 cases(18%)in the L-L group.The incidences of postoperative anastomotic complications and functional urinary complications were significantly lower in the L-L group.The 5-year survival rates in H-L and L-L groups were 81.7%and 81.6%,respectively,and relapse-free survival rates were 74.3%and 77.1%,respectively.The two groups were similar statistically.CONCLUSION Complete mesenteric resection combined with lymph node dissection around the inferior mesenteric artery root while preserving the LCA is a beneficial surgical approach during laparoscopic resection for colorectal cancer.

First case of cross-auxiliary double domino donor liver transplantation

We report a case of double domino liver transplantation in a 32-year-old woman who was diagnosed with familial amyloid polyneuropathy(FAP) and liver dysfunction. A two-stage surgical plan was designed, and one domino graft was implanted during each stage. During the firststage, an auxiliary domino liver transplantation was conducted using a domino graft from a 4-year-old female child with Wilson's disease. After removing the right lobe of the FAP patient's liver, the graft was rotated 90 degrees counterclockwise and placed along the right side of the inferior vena cava(IVC). The orifices of the left, middle, and right hepatic veins were reconstructed using an iliac vein patch and then anastomosed to the right side of the IVC. Thirty days later, a second domino liver graft was implanted. The second domino graft was from a 3-yearold female child with an ornithine carbamyl enzyme defect, and it replaced the residual native liver(left lobe). To balance the function and blood flow between the two grafts, a percutaneous transcatheter selective portal vein embolization was performed, and "the left portal vein" of the first graft was blocked 9 mo after the second transplantation. The liver function indices, blood ammonia, and 24-h urinary copper levels were normal at the end of a 3-year follow-up. These two domino donor grafts from donors with different metabolic disorders restored normal liver function. Our experience demonstrated a new approach for resolving metabolic disorders with domino grafts and utilizing explanted livers from children.

Effect of compound field on horizontal continuous casting of Al-1wt.%Si alloy

A travelling magnetic field, a power ultrasonic field, and a compound field were used separately during the horizontal continuous casting process of Al-1wt.%Si alloy. The samples obtained were characterized using an optical microscope, a scanning electron microscope, a tensile testing machine, and an electron probe microscopic analyzer to test the microstructures, properties, and element distribution of the samples. The results show that the application of a single fi eld can enhance the mechanical properties and reduce the segregation of Si element in Al-1wt.%Si alloy to some extent. The application of a compound field can obtain the best refi nement and homogeneity of the Si element in the alloy, leading to the highest increase of tensile strength and elongation among the three applied fi elds. The mechanism of the action of external fi elds on the refi nement of microstructures and homogeneity of the Si element is discussed and the compound fi eld is considered to be an effective method to achieve high quality Al alloys.

Factors associated with overall survival in early gastric cancer patients who underwent additional surgery after endoscopic submucosal dissection

BACKGROUND Controversy exists about the benefit of additional surgery after endoscopic submucosal dissection(ESD)for early gastric cancer(EGC).AIM To examine risk factors for overall survival(OS)after additional surgery in patients with EGC who initially underwent ESD.METHODS This was a retrospective analysis of patients with EGC who underwent additional surgery after ESD at the Beijing Friendship Hospital affiliated to Capital Medical University between August 2012 and August 2019.OS was the primary outcome.Lymph node metastasis and residual tumor were secondary outcomes.Logistic regression models and Kaplan-Meier curves were used for further analysis.RESULTS Forty-two patients were evaluated,including 35(83.3%)males and 7(16.7%)females.The mean age was 62(range,32-82)years.Male sex[hazard ratio(HR)=21.906,95%confidence interval(CI):3.762-229.250;P=0.039),T1b invasion(HR=3.965,95%CI:1.109-17.432;P=0.047),undifferentiated tumor(HR=9.455,95%CI:0.946-29.482;P=0.049),lymph node metastasis(HR=2.126,95%CI:0.002-13.266;P=0.031),and residual tumor(HR=4.275,95%CI:1.049-27.420;P=0.043)were independently associated with OS.The follow-up duration was 4-81 mo(median:50.7 mo).OS was 77.0±12.1 mo(95%CI:53.3-100.7 mo).The 3-year and 5-year OS rates were 94.1%and 85%,respectively.CONCLUSION Male sex,T1b invasion,undifferentiated tumor,lymph node metastasis,and residual tumor are independently associated with OS in patients with EGC who underwent additional surgery after ESD.

Current indications for endoscopic submucosal dissection of early gastric cancer

The development of endoscopic treatment technology has further promoted the minimally invasive treatment of early gastric cancer(EGC).Endoscopic treatment has achieved better therapeutic effects in terms of safety and prognosis and is the preferred treatment method for patients who meet the indications for endoscopic treatment.However,the consequent problem is that some patients receiving endoscopic treatment may undergo non-curative resection,and the principle of follow-up management for non-curative resection patients deserves further attention.In addition,there are still debates on how to improve the accuracy of clinical staging,select a reasonable treatment method for patients who meet the expanded indications for endoscopic treatment,manage patients with positive endoscopic surgical margins,conduct research on function-preserving surgery,and manage the treatment of EGC under the current situation in China.Consequently,we aim to review current indications for endoscopic submucosal dissection of EGC in order to better inform treatment options.

Inflammation-related indicators to distinguish between gastric stromal tumors and leiomyomas:A retrospective study

BACKGROUND Gastric leiomyomas and gastric stromal tumors are the most common types of gastric tumors encountered.In recent years,the incidence of the two types of tumors has been increasing,but the differential diagnosis is still a challenge in clinical work.However,as there are many reports on stromal tumors and inflammation-related indicators are gradually being paid attention to as important factors in predicting tumor prognosis,the two main purposes of this study were to explore the inflammation-related differences between the two types of tumors and to develop a nomogram as a predictive model.AIM To explore the differences in platelet-lymphocyte ratio(PLR),neutrophillymphocyte ratio(NLR),lymphocyte mononuclear cell ratio(LMR),and SII between the two types of tumors,and simultaneously create the nomogram model.METHODS This study enrolled 88 patients in the gastric stromal tumor group and 56 patients in the gastric leiomyoma group,and the relevant data of the two groups were entered into the system for an integrated analysis.The primary objective of this study was to identify the differences in the inflammation index between the two types of tumors.RESULTS There were statistically significant differences between the two groups in sex,age,and tumor location.In comparison,gastric leiomyomas seem to be more common in women,young patients,and gastric cardia,which is in line with our previous research;the groups showed the following statistical differences:PLR(158.2%vs 134.3%,P=0.028),NLR(2.35 vs 1.68,P=0.000),LMR(5.75 vs 10.8,P=0.004),and SII(546.2 vs 384.3,P=0.003).The results of the multivariate logistic regression analysis showed that sex,age,tumor location,and LMR were independent risk factors for the identification of the two types of tumors.After considering the risk factors selected by the above analysis into the predictive model,a predictive model for distinguishing gastrointestinal stromal tumors from gastric leiomyomas was established as the nomogram.CONCLUSION Gastric leiomyomas and gastric stromal tumors are not only different in factors such as age of the patient,but also in inflammatory indicators such as LMR and PLR.We have established a predictive model related to the laboratory indicators and are looking forward to further research conducted in this clinical area.

Malignant tumors associated with Peutz-Jeghers syndrome: Five cases from a single surgical unit

BACKGROUND Peutz-Jeghers syndrome(PJS) is an autosomal dominant inherited disease easily causing secondary malignant changes without effective treatments.AIM To assess the clinical characteristics, diagnosis, and treatment of malignant changes secondary to PJS.METHODS The clinical data of five patients with malignant changes secondary to PJS diagnosed and treated at Beijing Friendship Hospital from June 2014 to January 2017 were retrospectively analyzed;the follow-up ended in May 2018.RESULTS There were three male and two female patients with an average age of 43.6 years.Intestinal obstruction, intussusception, and abdominal pain were the first symptoms. Computed tomography and gastrointestinal imaging combined with endoscopy helped evaluate the depth of tumor infiltration and determine the need for radical resection. Three patients underwent surgery. Postoperative pathology confirmed adenocarcinoma, genetic test indicated STK11 mutation,and the patients received chemotherapy, including one who succumbed to tumor progression 6 months post-surgery. Other two patients underwent endoscopic resection, and postoperative pathology confirmed high grade intraepithelial neoplasia. The surviving patients had no recurrence by May 2018.CONCLUSION Endoscopy combined with computed tomography and gastrointestinal imaging is of great significance in the diagnosis and treatment of PJS, and pathological examination and gene detection are the gold standards for detecting malignant changes secondary to PJS. Some malignant polyps can be removed under endoscopy, and surgery is feasible when malignant polyps cannot be remove dunder an endoscope. For patients unable to achieve R0 resection, clinical symptoms should be relieved, and postoperative adjuvant chemotherapy could improve long-term prognosis. Meanwhile, close and regular surveillance should be conducted to prevent severe complications.

Role of abdominal drainage in bariatric surgery: Report of six cases

BACKGROUND Abdominal drainage allows for timely detection of hemorrhage,but it cannot prevent hemorrhage.Whether routine abdominal drainage is needed during bariatric procedures remains controversial.Few reports describe the role of abdominal drainage in the diagnosis and treatment of abdominal hemorrhage in bariatric surgery.CASE SUMMARY Six cases of hemorrhage after bariatric surgery were described,including three cases with and three without abdominal drainage during the first surgery.The hemorrhage in five of the six cases was controlled by conservative treatment.Abdominal hemorrhage was found through the drainage tube on the day of the operation in the three patients with abdominal drainage during the first surgery.Emergency treatment was initiated,and their conditions gradually stabilized within 48 h.No patients required a reoperation.Abdominal hemorrhage was found later in the patients without abdominal drainage.Although the hemorrhage was controlled by conservative treatment in two cases (1 and 2),reoperation and percutaneous drainage were performed for abdominal infection and pelvic hemorrhage.An obsolete encapsulated effusion that may require treatment in the future was left in the abdominal cavity of a patient (Case 1).CONCLUSION The possibility of controlling abdominal hemorrhage after bariatric/metabolic surgery by conservative treatment is high.When hemorrhage occurs,abdominal drainage can reduce the probability of reoperation by reducing the formation of blood clots behind the stomach.

Randomized Trial of Immediate Postoperative Pain Following Single-incision Versus Traditional Laparoscopic Cholecystectomy

Background： We undertook a randomized controlled trial to ascertain if single-incision laparoscopic cholecystectomy （SILC） was more beneficial for reducing postoperative pain than traditional laparoscopic cholecystectomy （TLC）. Moreover, the influencing factors of SI LC were analyzed. Methods： A total of 552 patients with symptomatic gallstones or polyps were allocated randomly to undergo SILC （n = 138） or TLC （n - 414）. Data on postoperative pain score, operative time, complications, procedure conversion, and hospital costs were collected. After a 6-month follow-up, all data were analyzed using the intention-to-treat principle. Results： Among SILC group, 4 （2.9%） cases required conversion to TLC. Mean operative time of SILC was significantly longer than that of TLC （58.97 ± 21.56 vs. 43.38 ± 19.02 min, P 〈 0.001）. The two groups showed no significant differences in analgesic dose, duration of hospital stay, or cost. Median pain scores were similar between the two groups 7 days after surgery, but SILC-treated patients had a significantly lower median pain score 6 h after surgery （10-point scale： 3 [2, 4] vs. 4 [3, 5], P = 0.009）. Importantly, subgroup analyses of operative time for SILC showed that a longer operative time was associated with greater prevalence of pain score 〉5 （≥100 min： 5/7 patients vs. 〈40 min, 3/16 patients, P = 0.015）. Conclusions： The primary benefit of SILC appears to be slightly less pain immediately after surgery. Surgeon training seems to be important because the shorter operative time for SILC may elicit less pain immediately after surgery.

Chinese guideline for the application of rectal cancer staging recognition systems based on artificial intelligence platforms (2021 edition)

Development and Application of Artificial Intelligence Recognition Systems in Rectal Cancer Staging Whether for surgical treatment or for neoadjuvant chemoradiotherapy,imaging evaluation has become an important basis to perform the treatment plans.[1]The reading of imaging results requires a large number of experienced radiologists to complete,but shortages and uneven distributions of personnel cause delays and biases in imaging results.Therefore,independent research and development of automatic recognition systems of rectal cancer staging based on artificial intelligence(AI)platforms aim to partially replace practitioners’work and achieve rapid and accurate identification of rectal cancer staging.

经肛全直肠系膜切除术:一项多中心队列研究

背景:经肛全直肠系膜切除术(taTME)已成为一种前景良好的直肠癌治疗新术式。taTME具有能提供一个更好的远端直肠游离路径和获得更高质量的切除标本等潜在优势。本研究旨在评估taTME的可行性,并总结10家中国医疗中心的初步经验。方法:211例taTME手术患者纳入研究。回顾性收集并分析taTME的安全性、可行性及肿瘤学指标。结果:本组直肠癌患者肿瘤距肛缘的中位距离是5.9 cm(范围,1.5-12 cm)。中位手术时间280 min(范围,70-600 min),中位术中失血量50 mL(范围,10-1500 mL)。总并发症发生率为27.9%。211例患者中,175例(82.9%)手术标本系膜完整,33例(15.6%)接近完整。97.7%的患者环周切缘为阴性。术后中位随访35个月(范围,2-86个月),16例(7.6%)死亡,13例(6.2%)局部复发,27例(12.8%)出现远处转移。Kaplan-Meier生存分析显示,本组病例1、2、3年无病生存率分别为94.8%、89.3%和80.2%,1、2、3年总生存率分别为97.4%、95.7%和92.9%。结论:尽管存在回顾性研究的固有缺陷,但本研究仍初步证实了taTME用于一些经严格选择的直肠癌病例的安全性和可行性。未来要加强数据记录的准确性和完整性。

Study on the Postoperative Pain Calls for More Methods to Control Potential Bias

We thank Dr. Liu et al. very much for their attention on our recent article. In that paper, we reported a prospective randomized clinical trial comparing otitcomes between traditional laparoscopic cholecysiectomy and single-incision laparoscopic cholecystectomy （SILC）. It revealed that the SILC-treated patients had a signilicantly lower pain score only at postoperative 6 hours, but at 24 hours and longer after surgery pain scores were not different between the two groups.

Simultaneous liver transplantation and sleeve gastrectomy: first reported case in East Asia

To The Editor:Bariatric surgery,as an effective treatment for patients with morbid obesity and its related metabolic diseases,is gaining increasing popularity.Non-alcoholic fatty liver disease (NAFLD) is a common comorbidity associated with morbid obesity.Growing evidence suggests that patients with non-alcoholic steatohepatitis are at high-risk of adverse outcomes such as cirrhosis and liver-related mortality.Liver function failure caused by NAFLD is predicted to become the most common reason for liver transplantation (LT) in the United States by 2025.[1] The estmated prevalence of obesity is 20% to 30% in LT recipients in the United States.[2] LT is the only radical treatment for end-stage liver disease.If patients with end-stage liver disease and morbid obesity cannot effectively control their body weight after LT,the donor liver will be at high-risk of NAFLD again.

疫情期间胃肠外科的应对策略与诊疗推荐:中国外科医师的经验分享

由严重急性呼吸综合征冠状病毒2(SARS-CoV-2)引起的COVID-19正在全球暴发。尽管SARS-CoV-2被认为主要是通过呼吸道飞沫传播,但最新研究发现其也可以通过粪/口途径传播,这也引起了大家对胃肠道病毒传播的担忧。因此,作为抗疫一线的中国胃肠外科医师,我们愿意分享一些抗疫期间的经验和教训。在疫情期间建立一个科学、合理的应对策略是非常必要的。本文中,我们就如何在继续提供胃肠外科医疗服务的同时尽可能从各个方面减少病毒传播,取得了中国多家机构的共识,包括胃肠外科门诊防护、胃肠外科病房防护、胃肠内镜中心防护以及围手术期管理模式的优化。我们的经验分享和诊治推荐或有助于全球仍处于疫区的胃肠外科建立自己的病毒防控策略。

Transanal total mesorectal excision for rectal cancer: a multicentric cohort study

In the original version of this manuscript,the following line in the abstract read:‘among the 211 patients,175(82.9%)had complete TME and 33(15.6%)had incomplete TME’.This has now been corrected to:‘among the 211 patients,175(82.9%)had complete TME and 33(15.6%)had near complete TME’.The author apologises for the error.