Machine learning identifies the risk of complications after laparoscopic radical gastrectomy for gastric cancer

BACKGROUND Laparoscopic radical gastrectomy is widely used,and perioperative complications have become a highly concerned issue.AIM To develop a predictive model for complications in laparoscopic radical gastrectomy for gastric cancer to better predict the likelihood of complications in gastric cancer patients within 30 days after surgery,guide perioperative treatment strategies for gastric cancer patients,and prevent serious complications.METHODS In total,998 patients who underwent laparoscopic radical gastrectomy for gastric cancer at 16 Chinese medical centers were included in the training group for the complication model,and 398 patients were included in the validation group.The clinicopathological data and 30-d postoperative complications of gastric cancer patients were collected.Three machine learning methods,lasso regression,random forest,and artificial neural networks,were used to construct postoperative complication prediction models for laparoscopic distal gastrectomy and laparoscopic total gastrectomy,and their prediction efficacy and accuracy were evaluated.RESULTS The constructed complication model,particularly the random forest model,could better predict serious complications in gastric cancer patients undergoing laparoscopic radical gastrectomy.It exhibited stable performance in external validation and is worthy of further promotion in more centers.CONCLUSION Using the risk factors identified in multicenter datasets,highly sensitive risk prediction models for complications following laparoscopic radical gastrectomy were established.We hope to facilitate the diagnosis and treatment of preoperative and postoperative decision-making by using these models.

Clinical efficacy and pathological outcomes of transanal endoscopic intersphincteric resection for low rectal cancer

BACKGROUND Transanal endoscopic intersphincteric resection(ISR)surgery currently lacks sufficient clinical research and reporting.AIM To investigate the clinical effectiveness of transanal endoscopic ISR,in order to promote the clinical application and development of this technique.METHODS This study utilized a retrospective case series design.Clinical and pathological data of patients with lower rectal cancer who underwent transanal endoscopic ISR at the First Affiliated Hospital of Xiamen University between May 2018 and May 2023 were included.All patients underwent transanal endoscopic ISR as the surgical approach.We conducted this study to determine the perioperative recovery status,postoperative complications,and pathological specimen charac-teristics of this group of patients.RESULTS This study included 45 eligible patients,with no perioperative mortalities.The overall incidence of early complications was 22.22%,with a rate of 4.44%for Clavien-Dindo grade≥III events.Two patients(4.4%)developed anastomotic leakage after surgery,including one case of grade A and one case of grade B.Postoperative pathological examination confirmed negative circumferential resection margins and distal resection margins in all patients.The mean distance between the tumor lower margin and distal resection margin was found to be 2.30±0.62 cm.The transanal endoscopic ISR procedure consistently yielded high quality pathological specimens.CONCLUSION Transanal endoscopic ISR is safe,feasible,and provides a clear anatomical view.It is associated with a low incidence of postoperative complications and favorable pathological outcomes,making it worth further research and application.

GnRH-a联合LNG-IUS对子宫内膜异位症术后患者血清ENA-78及MCP-1水平的影响

目的探讨促性腺激素释放激素激动剂(GnRH-a)联合左炔诺孕酮宫内缓释系统(LNG-IUS),对子宫内膜异位症(EMT)术后患者血清上皮细胞来源的中性粒细胞活化肽78(ENA-78)及单核细胞趋化因子1(MCP-1)水平的影响。方法选取2013年7月—2016年2月在南通大学第二附属医院实施腹腔镜手术的96例EMT患者作为研究对象,并分为对照组(单用GnRH-a)和观察组(GnRH-a联合LNGIUS),每组48例。采用门诊复查或电话随访的方式在治疗前(T0)及治疗第3(T1)、6(T2)、12(T3)及24(T4)个月记录患者疼痛视觉模拟评分(VAS)、血清ENA-78、MCP-1及糖类抗原125(CA125)水平,比较两组复发率和药物不良反应率的差异。结果两组不同时间点VAS评分、ENA-78、MCP-1及CA125有差异(P<0.05);两组间VAS评分、ENA-78、MCP-1及CA125有差异(P<0.05);两组VAS评分、ENA-78、MCP-1及CA125变化趋势有差异(P<0.05)。观察组复发率低于对照组(P<0.05);两组治疗期间无严重药物不良反应。结论GnRH-a联合LNG-IUS不仅可降低EMT患者术后血清ENA-78、MCP-1及CA125水平,缓解疼痛,降低术后复发率,同时还具有较高的安全性,值得临床推广应用。

Anatomical variation of infra-pyloric artery origination： A prospective multicenter observational study (IPA-Origin)

Objective： Infra-pyloric artery （IPA） is an important anatomical landmark in treatment of gastric cancer and is the key vessel for pylorus-preserving gastrectomy and subgroup of infra-pyloric lymph nodes. However, its anatomical variation is not thoroughly understood. Our study aimed to clarify the origination of the IPA. Methods： We did this prospective, multicenter, open-label, observational study at gastric surgery departments of 34 hospitals in China. Gastric cancer patients aged 18 years or older and scheduled to undergo elective total or distal gastrectomy were assigned. During the surgery, IPA dissecting and exposing the origination point with photographs or video clips were required. The primary outcome was the origination of the IPA. Analysis of variance, χ2 tests and Fisher＇s tests were used to analyze the differences between groups. The study is registered at Clinicaltrials.gov （No. NCT03071237）. Results： Between May 8 and July 31, 2017, 429 patients were assigned for the study, and 419 （97.7%） patients had the IPA dissected and recorded through photograph or video and were included in the primary outcome analysis. The median age was 62 years old, and 73.7% were male. Among the patients, 78.5% received laparoscopic surgery. Single IPA origination was identified in 398 （95.0%） patients, including gastroduodenal artery （GDA） in 154 （36.8%） patients, anterior superior pancreaticoduodenal artery （ASPDA） in 130 （31.0%） patients, and right gastroepiploic artery （RGEA） in 114 （27.2%） patients. Fifteen （3.6%） patients were identified with multiple IPA and 6 （1.4%） patients were identified as IPA absence. The differences in the distribution of surgical approach （P=0.003） and geographic area （P=0.030） were statistically significant. No difference was shown in sex, age, gastrectomy type, tumor location, and clinical T, N and M stage. Conclusions： Our study found that the IPA originates from GDA, ASPDA and RGEA in similar proportions. Laparoscopic surgery may be more helpful in dissection of the IPA than open surgery.

Onodera's Prognostic Nutritional Index is a novel and useful prognostic marker for gastrointestinal stromal tumors

BACKGROUND Immunoinflammatory markers such as the peripheral blood neutrophil-tolymphocyte ratio(NLR)and the platelet-to-lymphocyte ratio(PLR)have gained considerable attention as prognostic markers in gastrointestinal stromal tumors(GISTs).AIM To assess the prognostic value of Onodera’s Prognostic Nutritional Index(OPNI)for GISTs.METHODS All patients who had undergone surgical resection for a primary,localized GIST from 2009 to 2016 at our cancer center were initially and retrospectively identified.Recurrence-free survival(RFS)was calculated by the Kaplan-Meier method and compared by the log-rank test.We used multivariate Cox proportional hazard regression models to identify associations with outcome variables.RESULTS A total of 235 GISTs were identified and included for analysis under our inclusion criteria.Univariate and multivariate analyses both identified the OPNI as an independent prognostic marker,and the OPNI was associated with the primary site,tumor size,mitotic index,tumor rupture,necrosis,and modified NIH risk classification.Low OPNI(<51.30;hazard ratio=5.852;95% confidence interval:1.072–31.964;P=0.0414)was associated with worse RFS.The 2-and 5-year RFS rates of the patients with a low OPNI were 92.83% and 76.22%,respectively,whereas 100% and 98.41% were achieved by the patients with a high OPNI.CONCLUSION The preoperative OPNI is a novel and useful prognostic marker for GISTs.

Genome-wide identification of TPS genes in sesame and analysis of their expression in response to abiotic stresses

Trehalose and its precursor,trehalose-6-phosphate,play critical roles in plant metabolism and response to abiotic stresses.Trehalose-6-phosphate synthase(TPS)is a key enzyme in the trehalose synthesis pathway.Hence this study identified TPS genes in sesame(SiTPSs)and examined their expression patterns under various abiotic stresses.Totally,ten SiTPSs were identified and comprehensively characterized.SiTPSs were found to be unevenly distributed on five out of 13 sesame chromosomes and were predicted to be localized in chloroplasts and vacuoles of cells.Phylogenetic analysis classified SiTPS proteins into two groups(I and II),which was supported by gene structure and conserved motif analyses.Analysis of cis-acting elements in promoter regions of SiTPSs revealed that they might primarily involve developmental and environmental responses.SiTPSs exhibited different expression patterns in different tissues and under different abiotic stresses.Most group II SiTPS genes(SiTPS4-SiTPS10)were strongly induced by drought,salt,waterlogging,and osmotic stress.Particularly,SiTPS10 was the most significantly up-regulated under various abiotic stresses,indicating it is a candidate gene for improving sesame tolerance to multiple abiotic stresses.Our results provide insight into the TPS gene family in sesame and fundamental resources for genomics studies towards dissecting SiTPS genes’functions.

Large scale genetic landscape and population structure of Ethiopian sesame (Sesamum indicum L.) germplasm revealed through molecular marker analysis

Sesame(Sesamum indicum L.) plays a crucial role in Ethiopian agriculture,serving both subsistence and commercial purposes.However,our understanding of the extensive genetic diversity and population structure of Ethiopian sesame remains limited.To address this knowledge gap,we genotyped 368 Ethiopian sesame germplasms,categorizing into four distinct breeding groups:Accessions,landraces,improved varieties,and wild types,using a comprehensive set of 28 polymorphic markers,including 23 simple sequence repeat(SSR) and five Insertion-Deletion(InDel) markers.These markers ensured robust genomic representation,with at least two markers per linkage group.Our results unveiled substantial genetic diversity,identifying a total of 535 alleles across all accessions.On average,each locus displayed 8.83 alleles,with observed and expected heterozygosity values of 0.30 and 0.36,respectively.Gene Diversity and Polymorphic Information Content(PIC) were recorded at 0.37 and 0.35.The percentage of polymorphic loci varied significantly among breeding groups,ranging from8.00% to 82.40%,indicating high diversity in accessions(82.4%),moderate diversity in improved varieties(31.20%) and landraces(29.60%),and limited diversity in wild types(8.00).Analysis of Molecular Variance(AMOVA) results emphasized significant genetic differentiation among populations,with substantial diversity(P<0.001) within each population.Approximately 8% of the entire genetic diversity could be attributed to distinctions among populations,while the larger proportion of genetic diversity(92%) resided within each individual sesame population,showcasing heightened diversity within each group.Our study’s findings received support from both Bayesian clustering and Neighbor-joining(NJ) analysis,reaffirming the credibility of our genetic structure insights.Notably,Population structure analysis at its highest Δk value(k=2) revealed the existence of two primary genetic clusters,further subdivided into four sub-populations at k=4.Similarly,NJ analysis identified two prominent clusters,each displaying additional sub-clustering.In conclusion,our research provides a comprehensive understanding of genetic groups,subpopulations,and overall diversity within Ethiopian sesame populations.These findings underscore the significant genetic diversity and population structure within Ethiopian sesame germplasm collections.This genetic richness holds promise for breeding and conservation efforts,highlighting the importance of preserving genetic diversity to ensure adaptation to changing environments and meet the needs of farmers and consumers.

Effects of controlled superovulation on the expression of HOXA10,integrin αvβ3 and LIF in mice during peri-implantation

Objective:To observe the expression of endometrial homologous box gene A10(HOXA10),Integrinαvβ3 and leukemia suppressor factor(LIF)in peri-implantation mice,and to investigate the effect of controlled superovulation(COH)on endometrial receptivity in mice.Methods:After COH model preparation and blastocyst transplantation,kunming pure-bred mature mice were randomly divided into natural blastocyst+natural pseudocyst group,COH blastocyst+natural pseudocyst group,natural blastocyst+COH pseudocyst group,and COH blastocyst+COH pseudocyst group.The pregnancy rate and average number of beds in each group were observed on day 6 of conception.Western blot and RT-PCR were used to detect the expression of HOXA10,Integrinααvβ3,LIF protein and mRNA in the endometria of mice on day 5 of conception.Results:The pregnancy rate and average number of beds in the COH group were lower than those in the natural receptor group.The expression of HOXA10,Integrinααvβ3 and LIF in endometrium was significantly lower than that of the natural receptor mice(P<0.01).Conclusion:Superovulation drugs down-regulate the expression of HOXA10,Integrinαvβ3 and LIF in endometrium during the implantation window,reduce endometrial receptivity,and lead to low clinical pregnancy rate.

Risk factors for anastomotic leakage after gastrectomy for Siewert type Ⅱ/Ⅲ adenocarcinoma of the esophagogastric junction:a retrospective case-control study

Objective:To identify risk factors for anastomotic leakage after gastrectomy in patients with Siewert type II/III adenocarcinoma(AEG)of the esophagogastric junction.Methods:This was a retrospective case-control study of 903 patients with Siewert type II/III AEG treated from January 2012 to January 2015 at the Shanxi Cancer Hospital in China.All patients underwent gastrectomy,and their clinical characteristics were analyzed to identify associations with anastomotic leakage.Independent risk factors were identified by binary logistic regression.The 2-year disease-free survival was calculated and compared between patients with anastomotic leakage and control patients.The study was approved by the Institutional Review Board of Shanxi Medical University(approval No.2014-09-39)on September 19,2014.Results:Out of the 903 patients were included in the study,80(8.86%,80/903)experienced anastomotic leakage.The mortality rate attributed to anastomotic leakage was 8.75%(7/80).Logistic regression analysis revealed that preoperative hypoalbuminemia(odds ratio(OR)=3.249,95%confidence interval(CI):1.569-6.725,P=0.002),type of reconstruction(OR=1.795,95%CI:1.026-3.142,P=0.040),and combined organ resection(OR=1.807,95%CI:1.069-3.055,P=0.027)were independent risk factors for anastomotic leakage.Conclusion:Preoperative hypoalbuminemia,type of reconstruction,and combined organ resection were identified as risk factors for anastomotic leakage in patients undergoing gastrectomy for Siewert type Ⅱ/Ⅲ AEG.

The OsSRO1c-OsDREB2B complex undergoes protein phase transition to enhance cold tolerance in rice

Cold stress is one of the major abiotic stress factors affecting rice growth and development,leading to significant yield loss in the context of global climate change.Exploring natural variants that confer cold resistance and the underlying molecular mechanism responsible for this is the major strategy to breed cold-tolerant rice varieties.Here,we show that natural variations of a SIMILAR to RCD ONE(SRO)gene,OsSRO1c,confer cold tolerance in rice at both seedling and booting stages.Our in vivo and in vitro experiments demonstrated that OsSRO1c possesses intrinsic liquid–liquid phase-separation ability and recruits OsDREB2B,an AP2/ERF transcription factor that functions as a positive regulator of cold stress,into its biomolecular condensates in the nucleus,resulting in elevated transcriptional activity of OsDREB2B.We found that the OsSRO1c-OsDREB2B complex directly responds to low temperature through dynamic phase transitions and regulates key cold-response genes,including COLD1.Furthermore,we showed that introgression of an elite haplotype of OsSRO1c into a cold-susceptible indica rice could significantly increase its cold resistance.Collectively,our work reveals a novel cold-tolerance regulatory module in rice and provides promising genetic targets for molecular breeding of cold-tolerant rice varieties.

年龄调整的Charlson合并症指数影响腹腔镜胃癌根治术患者预后的多中心回顾性研究

目的探讨年龄调整的Charlson合并症指数(ACCI)对腹腔镜胃癌根治术患者预后的影响。方法采用回顾性队列研究方法。收集2016年9月至2017年10月中国腹腔镜胃肠外科研究组-04研究中19家医院收治的242例(福建医科大学附属协和医院54例、莆田市第一医院32例、上海交通大学医学院附属仁济医院32例、福建医科大学附属漳州市医院31例、南方医科大学南方医院17例、南京医科大学第一附属医院11例、青海大学附属医院8例、梅州市人民医院8例、福建省立医院7例、复旦大学附属中山医院6例、龙岩市第一医院6例、新疆医科大学附属第一医院5例、陆军军医大学第一附属医院5例、广州中医药大学第二附属医院4例、四川大学华西医院4例、北京大学肿瘤医院4例、厦门大学附属第一医院3例、广东省人民医院3例、西安交通大学第一附属医院2例)行腹腔镜胃癌根治术患者的临床病理资料;男193例,女49例;年龄为62(23~74)岁。观察指标:(1)患者年龄分布与合并症及ACCI情况。(2)ACCI分组及临床病理特征比较。(3)术后早期并发症发生情况及术后早期并发症影响因素分析。(4)随访情况。(5)影响患者3年无复发生存率的因素分析。采用门诊或电话方式进行随访,了解患者术后生存情况。随访时间截至2020年12月。正态分布的计量资料以x±s表示,组间比较采用t检验;偏态分布的计量资料以M(Q_(1),Q_(3))或M(范围)表示,组间比较采用Mann-Whitney U检验。计数资料以绝对数或百分比表示,组间比较采用χ^(2)检验或Fisher确切概率法。等级资料比较采用非参数秩和检验。采用X-Tile软件(3.6.1)分析ACCI分组临界值。采用Kaplan-Meier法计算生存率和绘制生存曲线,采用Log-Rank检验进行生存分析。采用Logistic回归模型分析术后早期并发症影响因素。采用COX比例风险模型进行3年无复发生存率影响的单因素和多因素分析,多因素分析以逐步回归法纳入P<0.05的单因素指标和临床上与预后密切相关的变量。结果(1)患者年龄分布与合并症及ACCI情况。242例患者中,<50岁28例,50~59岁68例,60~69岁113例,70~79岁33例;合并轻度肝病、伴有终末器官损害的糖尿病、脑血管疾病、消化性溃疡、充血性心力衰竭、慢性肺疾病、不伴终末器官损害的糖尿病分别为1、1、2、2、6、8、9例。242例患者ACCI为2(0~4)。(2)ACCI分组及其临床病理特征比较。X-Tile软件分析结果显示:ACCI=3为最佳分组临界值。根据ACCI最佳分组临界值将242例患者分为低ACCI组(ACCI<3)194例和高ACCI组(ACCI≥3)48例。低ACCI组患者年龄,体质量指数,术前合并症,美国麻醉医师协会分级(Ⅰ级、Ⅱ级、Ⅲ级),肿瘤长径,组织学类型(印戒细胞癌或低分化腺癌、中分化或高分化腺癌),肿瘤病理学T分期(T1期、T2期、T3期、T4期),化疗周期分别为(58±9)岁,(22.6±2.9)kg/m2,31例,106、85、3例,(4.0±1.9)cm,104、90例,16、29、72、77例,6(4,6)个;高ACCI组患者上述指标分别为(70±4)岁,(21.7±2.7)kg/m2,23例,14、33、1例,(5.4±3.1)cm,36、12例,3、4、13、28例,4(2,5)个;两组患者上述指标比较,差异均有统计学意义(t=-14.37、1.98,χ^(2)=22.64,Z=-3.11,t=-2.91,χ^(2)=7.22,Z=-2.21、-3.16,P<0.05)。(3)术后早期并发症发生情况及术后早期并发症影响因素分析。242例患者中,33例发生术后早期并发症,包括局部并发症20例,系统性并发症16例,部分患者同时合并多种并发症。20例局部并发症包括腹腔感染12例,吻合口漏7例,切口感染、腹腔出血、吻合口出血各2例,淋巴液漏1例。16例系统性并发症包括肺部感染11例,心律失常、脓毒血症各2例,肝衰竭、肾衰竭、肺动脉栓塞、深静脉血栓、尿路感染、尿潴留各1例。33例发生术后早期并发症患者Clavien-Dindo并发症分级Ⅰ级、Ⅱ级、Ⅲa级、Ⅲb级、Ⅳ级分别为3、22、5、2、1例。低ACCI组患者术后早期并发症、局部并发症、系统性并发症分别为22、13、9例;高ACCI组患者上述指标分别为11、7、7例;两组患者早期并发症、系统性并发症比较,差异均有统计学意义(χ^(2)=4.38,4.66,P<0.05);局部并发症比较,差异无统计学意义(χ^(2)=2.20,P>0.05)。Logistic回归分析结果显示:ACCI是影响腹腔镜胃癌根治术后发生早期并发症的相关因素(比值比=2.32,95%可信区间为1.04~5.21,P<0.05)。(4)随访情况。242例患者均获得随访,随访时间为36(1~46)个月。随访期间,53例患者死亡,13例带瘤生存。242例患者3年无复发生存率为73.5%。低ACCI组患者随访时间为36(2~46)个月,随访期间,29例患者死亡,10例带瘤生存,患者3年无复发生存率为80.0%;高ACCI组患者上述指标分别为35(1~42)个月,24、3例,47.4%;两组患者3年无复发生存率比较,差异有统计学意义(χ^(2)=30.49,P<0.05)。(5)影响患者3年无复发生存率的因素分析。单因素分析结果显示:术前合并症、ACCI、肿瘤长径、组织学类型、血管侵犯、淋巴管侵犯、神经侵犯、肿瘤病理学TNM分期、术后早期并发症是影响腹腔镜胃癌根治术后3年无复发生存率的相关因素(风险比=2.52,3.64,2.62,0.47,2.87,1.90,1.86,21.77,1.97,95%可信区间为1.52~4.17,2.22~5.95,1.54~4.46,0.27~0.80,1.76~4.70,1.15~3.12,1.10~3.14,3.01~157.52,1.11~3.50,P<0.05)。多因素分析结果显示:ACCI、肿瘤病理学TNM分期、辅助化疗是腹腔镜胃癌根治术后3年无复发生存率的独立影响因素(风险比=3.65,11.00,40.66,0.39,95%可信区间为2.21~6.02,1.40~86.73,5.41~305.69,0.22~0.68,P<0.05)。结论ACCI是影响腹腔镜胃癌根治术后发生早期并发症的相关因素,ACCI、肿瘤病理学TNM分期、辅助化疗是腹腔镜胃癌根治术后3年无复发生存率的独立影响因素。

Postoperative abdominal complications of gastric and colorectal cancer surgeries in China: a multicentered prospective registry-based cohort study

Surgical quality is critical in cancer treatment,as it not only determines the radical resection of the primary tumor but also allows expedited postoperative recovery and early continuation of adjuvant therapy.Postoperative complications are valuable met-rics for assessing surgical quality.In gastric and colorectal cancer surgeries,postoperative complications substantially postpone patients'recovery and,in extreme cases,pose life-threatening risks[1].

Application and Experiment on the Least-action Principle of Explosive Welding of Stainless Steel/Steel

In nature, many physical phenomena follow the least-action principle, which is also abided by the course of explosive welding of stainless steel/steel. The optimal welding interface can be obtained with the least explosive charge by theoretical analysis and interface test. The bonding energy can be acknowledged as the ＂action＂ in explosive welding. To minimize the bonding energy, these rules must be followed such as the lower limit of explosive charge, the upper limit of span and the explosive of critical explosion velocity. The principle of least-action is achieved in the course of explosive welding, and the interface will be optimum.

Targeting slug-mediated non-canonical activation of c-Met to overcome chemo-resistance in metastatic ovarian cancer cells

Metastasis-associated drug resistance accounts for high mortality in ovarian cancer and remains to be a major barrier for effective treatment. In this study, SKOV3/T4, a metastatic subpopulation of ovarian cancer SKOV3 cells, was enriched to explore potential interventions against metastaticassociated drug resistance. Quantitative genomic and functional analyses were performed and found that slug was significantly increased in the SKOV3/T4 subpopulation and contributed to the high resistance of SKOV3/T4. Further studies showed that slug activated c-Met in a ligand-independent manner due to elevated levels of fibronectin and provoked integrin α V function, which was confirmed by the significant correlation of slug and p-Met levels in 121 ovarian cancer patient samples. Intriguingly,c-Met inhibitor(s) exhibited greatly enhanced anti-cancer effects in slug-positive ovarian cancer models both in vitro and in vivo. Additionally, IHC analyses revealed that slug levels were highly correlated with reduced survival of ovarian cancer patients. Taken together, this study not only uncovers the critical roles of slug in drug resistance in ovarian cancer but also highlights a promising therapeutic strategy by targeting the noncanonical activation of c-Met in slug-positive ovarian cancer patients with poor prognosis.

Power electronic transformer with adaptive PLL technique for voltage-disturbance ride through

The power electronic transformer(PET) has recently emerged as a type of power converter. It features the basic functions of power conversion and isolation as well as additional functions related to power quality control. A novel PET for a distribution grid called a flexible power distribution unit is proposed in this paper, and the energy exchange mechanism between the network and the load is revealed. A 30 kW 600 VAC/220 VAC/110 VDC medium-frequency isolated prototype is developed and demonstrated. This paper also presents key control strategies of the PET for electrical distribution grid applications,especially under grid voltage disturbance conditions.Moreover, stability issues related to the grid-connected three-phase PET are discussed and verified with an impedance-based analysis. The PET prototype is tested, and it passes the voltage-disturbance ride-through function. The experimental results verify the power quality control abilities of the PET.

Lower limit law of welding windows for explosive welding of dissimilar metals

The influence of explosive charge thickness on the quality of explosive welding of dissimilar metals was investigated.The lower limit law should be followed in the course of explosive welding.Three welding experiments of stainless steel（410S）and steel（Q345R）were carried out in three different kinds of explosive charge thicknesses,namely 15,25and 35mm.Interfaces of morphology and mechanical properties of three samples were observed and tested.It was found that micro and small wavy bonding is mainly formed for charge thickness of 15mm whose strength is the highest with minor deformation and few defects in the interface;small and middle wavy bonding are mainly formed for charge thickness of 25 mm whose strength is comparatively mediocre;big wavy bonding is mainly formed for charge thickness of 35 mm whose strength is the lowest.The cause of high bonding strength of the micro and small wavy interface was analyzed and verified on the basis of the results of Electron Probe Micro-Analyzer（EPMA）tests of three selected samples.

Ultrasound delivery of Chinese rhubarb promotes early recovery of gastrointestinal function after gastrectomy:a prospective randomized controlled study

Objective: Chinese rhubarb is a promising Chinese medicine for the promotion of gastrointestinal function. This study was conducted to investigate the safety and efficacy of Chinese rhubarb administered via ultrasound delivery in promoting the early recovery of gastrointestinal function after gastrectomy.Methods: In this prospective randomized controlled study, 100 patients who were scheduled to undergo total or subtotal gastrectomy in Changzhi People’s Hospital or Subei People’s Hospital from August 2017 to January 2018 were recruited. These patients were randomly assigned into two equal groups before surgery: 50 in the experimental (Chinese rhubarb) group, and 50 in the control (routine nursing) group. After surgery, time to flatus, bowel movement, clear liquid diet, and removal of nasogastric tube were recorded and analyzed. In addition, postoperative pain, postoperative bowel movement-related complications, and postoperative hospital stay duration were also recorded and analyzed. The study was approved by The protocol was approved by the Institutional Review Board of Changzhi People’s Hospital and Subei People’s Hospital on July 1, 2017 and registered with the Chinese Clinical Trial Registry on December 17, 2018 (registration number: ChiCTR1800020143).Results: Time to flatus (control group 85.68±22.00 hours vs experimental group 73.06±23.42 hours;P=0.007), bowel movement (5.52±1.56 vs 4.40±1.21 days;P<0.001), clear liquid diet (6.72±1.16 vs 6.22±1.28 days;P=0.044), and removal of nasogastric tube (6.30±1.52 vs 5.65±1.58 days;P=0.044) were significantly shorter in the experimental group compared with the control group, as was the postoperative hospital stay duration (14.30±3.46 vs 12.86±1.36 days;P=0.006). In addition, better pain relief (P=0.003) and a lower incidence of postoperative bowel movement-related complications (6 vs 21;P=0.001) were noted in the experimental group.Conclusion: Ultrasound delivery of Chinese rhubarb is useful to promote the early recovery of gastrointestinal function after gastrectomy.

Several Enantiopure Chiral Building Blocks Derived from D-Mannose and a Formal Synthesis of Dubiusamine C

Several multi-functional chiral building blocks derived from D-mannose are developed, which may find diverse utilities as sources of 1-hydroxy-3-methyl structural units in enantioselective synthesis of many natural products. A formal synthesis of natural dubiusamine-C is also presented.

Infrapyloric lymph node metastasis pattern in middle/lower gastric cancer:an exploratory analysis of a multicenter prospective observational study(IPA-ORIGIN)

To the Editor:Gastric cancer is one of the most common cancers in China.It is mainly found in the middle/lower part of the stomach,[1]where it commonly metastasizes from the infrapyloric lymph node(No.6).Previous studies reported that the risk of No.6 lymph node metastasis was different based on tumor locations.In lower gastric cancer patients,the metastatic rate of No.6 lymph node can reach up to 18.7%,and in upper gastric cancer,the rate is merely 1.9%.[2]The distance between the primary tumor and the pylorus was proved to be related to No.6 lymph node metastasis.However,most of the studies were retrospective and their lymph nodes dissection’s quality control was controversial.