[Short-term outcomes of the TRIANGLE operation after neoadjuvant chemotherapy in locally advanced pancreatic cancer].

Objective: To investigate the safety and efficacy of the TRIANGLE operation after neoadjuvant chemotherapy in locally advanced pancreatic cancer(LAPC). Methods: This study is a retrospective case series analysis. Between January 2020 and December 2022, a total of 103 patients were diagnosed as LAPC who underwent neoadjuvant chemotherapy at the Pancreas Center, the First Affiliated Hospital of Nanjing Medical University. Among them, 26 patients (25.2%) underwent the TRIANGLE operation. There were 15 males and 11 females,with a age of (59±7) years (range: 49 to 74 years). The pre-treatment serum CA19-9(M(IQR)) was 248.8(391.6)U/ml (range: 0 to 1 428 U/ml),and the serum carcinoembryonic antigen was 4.1(3.8)µg/L(range: 1.4 to 13.4 µg/L). The neoadjuvant chemotherapy regimens included: mFOLFIRINOX regimen in 6 cases(23.1%), GnP regimen in 14 cases(53.8%), and mFOLFIRINOX+GnP regimen in 6 cases(23.1%). The follow-up duration extended until June 2023 or until the occurrence of the patient's death or loss to follow-up. The Kaplan-Meier method was employed to estimate the 1-year and 3-year overall survival rates. Results: After neoadjuvant chemotherapy,CA19-9 levels decreased by 92.3(40.1)%(range:2.1% to 97.7%). Evaluation of the response to treatment revealed 13 cases(50.0%) of stable disease,11 cases(42.3%) of partial response,and 2 cases(7.7%) of complete response. The surgical operation consisted of 12 cases(46.2%) of pancreaticoduodenectomy,12 cases(46.2%) of distal pancreatectomy,and 2 cases(7.7%) of total pancreatectomy. Margin determination was based on the "standardised pathology protocol" and the "1 mm" principle. No R2 and R1(direct) resections were observed,while the R0 resection rate was 61.5%(16/26), and the R1(1 mm) resection rate was 38.5%(10/26).The R1(1 mm) resection rates for the anterior margin,posterior margin,transected margin,portal vein groove margin,and uncinate margin were 23.1%(6/26),19.2%(5/26),12.5%(3/24),2/14, and 1/12, respectively. The overall postoperative complication rate was 57.8%(15/26),with major complications including grade B/C pancreatic fistula 25.0%(6/24,excluding 2 cases of total pancreatectomy),delayed gastric emptying in 23.1%(6/26),wound complications 11.5%(3/26),postoperative hemorrhage 7.7%(2/26), chylous fistula 7.7%(2/26) and bile fistula 3.8%(1/26). No reoperation was performed during the perioperative period(<90 days). One patient died on the 32nd day postoperatively due to a ruptured pseudoaneurysm. A total of 25 patients were followed up,with a follow-up time of 21(24)months(range: 8 to 42 months). During the follow-up period,8 cases(32.0%) died due to tumor recurrence and metastasis,while 17 patients(68.0%) remained alive,including 11 cases of disease-free survival,5 cases of distant metastasis,and 1 case of local recurrence. The overall survival rates at 1- and 3-year after the initiation of neoadjuvant chemotherapy were 95.8% and 58.9%, respectively. The overall survival rates at 1- and 3-year after surgery were 77.7% and 57.8%, respectively. Conclusion: Performing pancreatoduodenectomy according to the Heidelberg triangle protocol in LAPC patients after neoadjuvant chemotherapy might increase the R0 resection rate without increasing perioperative mortality or the incidence of major postoperative complications.

[Distal pancreatectomy with celiac axis resection for pancreatic body cancer: a single center review of 89 consecutive cases].

Objective: To investigate the clinical efficacy of distal pancreatectomy with celiac axis resection(DP-CAR). Methods: A total of 89 consecutive patients (50 males and 39 females) who were diagnosed with pancreatic body cancer and underwent DP-CAR in Pancreas Center,First Affiliated Hospital of Nanjing Medical University between September 2013 and June 2022 were retrospectively reviewed. There were 50 males and 39 females,with age(M(IQR)) of 63(12) years(range:43 to 81 years). Perioperative parameters,pathology results and follow-up data of these patients were analyzed,χ2 or Fisher's test for categorical data while the Wilcoxon test for quantitative data. Survival results were estimated by the Kaplan-Meier survival method. Results: Among 89 cases,cases combined with portal vein-superior mesenteric vein or organ resection accounted for 22.5% (20/89) and 42.7% (38/89),respectively. The operative time,blood loss and postoperative hospital stay were 270 (110) minutes,300 (300) ml and 13 (10) days,respectively. The overall morbidity rate was 67.4% (60/89) while the major morbidity was 11.2% (10/89). The increase rate in transient liver enzymes was 42.7% (38/89),3.4% (3/89) for liver failure,53.9% (48/89) for clinically relevant postoperative pancreatic fistula,1.1% (1/89) for bile leak,3.4% (3/89) for chylous leak of grade B and C,11.2% (10/89) for abdominal infection,9.0% (8/89) for postoperative hemorrhage of grade B and C,4.5% (4/89) for delayed gastric emptying,6.7% (6/89) for deep vein thrombosis,3.4% (3/89) for reoperation,4.5% (4/89)for hospital mortality,7.9% (7/89) for 90-day mortality. The pathological type was pancreatic cancer for all 89 cases and pancreatic ductal adenocarcinoma made up 92.1% (82/89). The tumor size was 4.8(2.0) cm, ranging from 1.5 to 12.0 cm. The number of lymph nodes harvested was 14 (13)(range:2 to 33),with a positive lymph node rate of 13.0% (24.0%). The resection R0 rate was 30.0% (24/80) and the R1 (<1 mm) rate was 58.8% (47/80). The median overall survival time was 21.3 months (95%CI: 15.6 to 24.3) and the median disease-free survival time was 19.1 months (95%CI: 11.7 to 25.1). The overall survival at 1-year and 2-year were 69.60% and 39.52%. The median survival time of 58 patients with adjuvant chemotherapy was 24.3 months (95%CI: 17.8 to 32.3) while that of 13 patients without any kind of adjuvant therapy was 8.4 months (95%CI: 7.3 to 22.3). Seven patients accepted neoadjuvant chemotherapy and there was no significant morbidity among them,with a resection rate of R0 of 5/7. Conclusion: DP-CAR is safe and feasible for selective cases,which could be more valuable in improving long-term survival when combined with (neo) adjuvant therapy.

[Clinical value of lymph node dissection of No. 14cd during pancreaticoduodenectomy in patients with pancreatic head carcinoma].

Objectives: To evaluate the positive rate of left posterior lymph nodes of the superior mesenteric artery (14cd-LN) in patients undergoing pancreaticoduodenectomy for pancreatic head carcinoma,to analyze the impact of 14cd-LN dissection on lymph node staging and tumor TNM staging. Methods: The clinical and pathological data of 103 consecutive patients with pancreatic cancer who underwent pancreaticoduodenectomy at Pancreatic Center,the First Affiliated Hospital of Nanjing Medical University from January to December 2022 were analyzed,retrospectively. There were 69 males and 34 females,with an age(M (IQR))of 63.0 (14.0) years (range:48.0 to 86.0 years). The χ2 test and Fisher's exact probability method was used for comparison of the count data between the groups,respectively. The rank sum test was used for comparison of the measurement data between groups. Univariate and multivariate Logistic regression analyzes were used for the analysis of risk factors. Results: All 103 patients underwent pancreaticoduodenectomy successfully using the left-sided uncinate process and the artery first approach. Pathological examination showed pancreatic ductal adenocarcinoma in all cases. The location of the tumors was the pancreatic head in 40 cases,pancreatic head-uncinate in 45 cases,and pancreatic head-neck in 18 cases. Of the 103 patients,38 cases had moderately differentiated tumor and 65 cases had poorly differentiated tumor. The diameter of the lesions was 3.2 (0.8) cm (range:1.7 to 6.5 cm),the number of lymph nodes harvested was 25 (10) (range:11 to 53),and the number of positive lymph nodes was 1 (3) (range:0 to 40). The lymph node stage was stage N0 in 35 cases (34.0%),stage N1 in 43 cases (41.7%),and stage N2 in 25 cases (24.3%). TNM staging was stage ⅠA in 5 cases (4.9%),stage ⅠB in 19 cases (18.4%),stage ⅡA in 2 cases (1.9%),stage ⅡB in 38 cases (36.9%),stage Ⅲ in 38 cases (36.9%),and stage Ⅳ in 1 case (1.0%). In 103 patients with pancreatic head cancer,the overall positivity rate for 14cd-LN was 31.1% (32/103),and the positive rates for 14c-LN and 14d-LN were 21.4% (22/103) and 18.4% (19/103),respectively. 14cd-LN dissection increased the number of lymph nodes (P<0.01) and positive lymph nodes (P<0.01). As a result of the 14cd-LN dissection,the lymph node stage was changed in 6 patients,including 5 patients changed from N0 to N1 and 1 patient changed from N1 to N2. Similarly,the TNM stage was changed in 5 patients,including 2 patients changed from stage ⅠB to ⅡB,2 patients changed from stage ⅡA to ⅡB,and 1 patient changed from stage ⅡB to Ⅲ. Tumors located in the pancreatic head-uncinate (OR=3.43,95%CI:1.08 to 10.93,P=0.037) and the positivity of 7,8,9,12 LN (OR=5.45,95%CI:1.45 to 20.44,P=0.012) were independent risk factors for 14c-LN metastasis; while tumors with diameter >3 cm (OR=3.93,95%CI:1.08 to 14.33,P=0.038) and the positivity of 7,8,9,12 LN (OR=11.09,95%CI:2.69 to 45.80,P=0.001) were independent risk factors for 14d-LN metastasis. Conclusion: Due to its high positive rate in pancreatic head cancer,dissection of 14cd-LN during pancreaticoduodenectomy should be recommended,which can increase the number of lymph nodes harvested,provide a more accurate lymph node staging and TNM staging.

[Comparison of distal pancreatectomy with celiac axis resection and sub-adventitial divestment technique for locally advanced or borderline resectable pancreatic body cancer].

Objective: To compare the outcomes of modified Appleby procedure and sub-adventitial divestment technique for locally advanced or borderline resectable pancreatic body cancer. Methods: A total of consecutive 58 patients(33 males and 25 females) who were diagnosed as locally advanced or borderline resectable pancreatic body cancer and underwent distal pancreatectomy at Pancreas Center, First Affiliated Hospital of Nanjing Medical University between September 2013 and May 2019 were retrospectively reviewed. The age(M(IQR)) was 62(9)years(range: 43 to 79 years). Thirty-one patients underwent distal pancreatectomy with celiac axis resection (DP-CAR) and 27 patients underwent distal pancreatectomy with sub-adventitial divestment technique(SDT). Perioperative parameters and follow-up data of these patients were analyzed. Quantitative data were compared with Wilcoxon test while categorical variables were compared with χ2 test or Fisher's exact test. Survival results were estimated by the Kaplan-Meier survival method with a Log-rank test. Results: There were no differences in age,gender,body mass index,abdominal symptoms,comorbidity or preoperative serum CA19-9 between two groups(all P>0.05). Obvious preoperative weight loss was more common in the group of SDT(48.1%(13/27) vs. 19.4%(6/31),χ²=5.431,P=0.020). Longer operative time(310(123) minutes vs. 254(137)minutes, Z=2.277,P=0.023),higher rate of combined organ resection(41.9%(13/31) vs. 14.8%(4/27),χ²=5.123,P=0.041) and longer postoperative hospital stay(15(10) days vs. 11(5)days,Z=2.292,P=0.022) were observed in the group of DP-CAR. Moreover,rate of overall morbidities was also higher (71.0%(22/31) vs. 29.6%(8/27),χ2=9.876,P=0.003),implicated by clinically relevant postoperative pancreatic fistula(61.3%(19/31) vs. 29.6%(8/27),χ2=5.814,P=0.020) in the DP-CAR group. Tumor size of the DP-CAR group was bigger(4.9(1.5)cm vs. 4.0(1.2)cm,Z=2.343,P=0.019) but no difference was seen between the DP-CAR group and SDT group in R0+R1(<1 mm) resection rate (84.0%(21/25) vs. 90.0%(18/20),P=0.678) and LNR(12.0(23.0)% vs. 9.0(18.0)%,Z=1.238,P=0.216),as well as median disease free survival(11.7 months vs. 11.4 months,Z=0.019,P=0.892) and median overall survival(16.3 months vs. 13.7 months,Z=0.172,P=0.679). Conclusions: Both DP-CAR and distal pancreatectomy with SDT are relatively safe and feasible for locally advanced or borderline resectable pancreatic body cancer. Compared with arterial resection,SDT may contribute to lower rates of postoperative complications and shorter duration of hospitalization,but no significant benefit is seen in long-term survival.

[Comparative clinical efficacy analysis of pancreatoduodenectomy for distal bile duct and pancreatic head cancer: a report of 1 005 cases].

Objective: To compare and analyze the clinical efficacy of pancreaticoduodenectomy for distal bile duct cancer and pancreatic head cancer. Methods: Clinical data of 1 005 patients who underwent pancreaticoduodenectomy and postoperative pathological examination confirmed the diagnosis of distal bile duct cancer and pancreatic head cancer at the Pancreas Center of the First Affiliated Hospital of Nanjing Medical University from January 2016 to December 2020 were analyzed retrospectively. There were 112 cases in the distal bile duct cancer group, 71 males and 41 females,with age (M(IQR)) of 65(15) years(range: 40 to 87 years); 893 cases in the pancreatic head cancer group, 534 males and 359 females,with age of 64(13)years(range: 16 to 91 years). The differences between clinicopathological characteristics and postoperative overall survival of the two groups were analyzed by χ2 test, Fisher's exact probability method, rank sum test or log-rank test, respectively. The difference in postoperative overall survival between the two groups was compared using Kaplan-Meier method after propensity score matching (1∶1). Results: Compared with the pancreatic head cancer group,the distal bile duct cancer group had shorter operative time (240.0(134.0) minutes vs. 261.0(97.0) minutes, Z=2.712, P=0.007),less proportion of combined venous resection (4.5% (5/112) vs. 19.4% (173/893), χ²=15.177,P<0.01),smaller tumor diameter (2.0(1.0) cm vs. 3.0(1.5) cm,Z=10.567,P<0.01),higher well/moderate differentiation ratio (51.4% (56/112) vs. 38.0% (337/893), χ²=7.328, P=0.007),fewer positive lymph nodes (0(1) vs. 1(3), Z=5.824, P<0.01),and higher R0 resection rate (77.7% (87/112) vs. 38.3%(342/893), χ²=64.399, P<0.01),but with a higher incidence of overall postoperative complications (50.0% (56/112) vs. 36.3% (324/892), χ²=7.913,P=0.005),postoperative pancreatic fistula (28.6% (32/112) vs. 13.9% (124/893), χ²=16.318,P<0.01),and postoperative abdominal infection (21.4% (24/112) vs. 8.6% (77/892), χ²=18.001,P<0.01). After propensity score matching, there was no statistical difference in postoperative overall survival time between patients in the distal bile duct cancer group and the pancreatic head cancer group (50.6 months vs. 35.1 months,Z=1.640,P=0.201),and multifactorial analysis showed that tumor site was not an independent risk factor affecting the prognosis of patients in both groups after matching (HR=0.73,95%CI:0.43 to 1.23,P=0.238). Conclusions: Patients with distal bile duct cancer are more likely to benefit from early diagnosis and surgical treatment than patients with pancreatic head cancer,but with a relative higher postoperative complication rates. The different tumor origin site is not an independent risk factor for prognosis of patients with distal bile duct cancer and pancreatic head cancer after propensity score matching.

[Application of left-sided uncinate process first approach in pancreaticoduodenectomy].

Objective: To evaluate the value of left-sided uncinate process first approach in pancreaticoduodenectomy. Methods: The clinical data of 152 patients who underwent the left-sided uncinate process first approach during pancreaticoduodenectomy at Pancreas Center, the First Affiliated Hospital of Nanjing Medical University from January 2020 to December 2020 were analyzed retrospectively. There were 64 females and 88 males,with age(M(QR)) of 62.0(14.7)years(range:16.0 to 84.0 years). The clinical date of 117 patients who underwent pancreaticoduodenectomy without using left-sided uncinate process first approach in the same period was selected as the control group,including 65 females and 52 males,with age of 64.0(13.0) years(range:13.0 to 84.0 years). Fisher exact probability method and t test were used to compare the data between the two groups,rank sum test was used for comparison of continuous variables between the two groups. Results: Pancreaticoduodenectomy was successfully performed in 152 patients in left-sided uncinate process first approach group. The operation time was 222.5(77.0) minutes(range:117.0 to 480.0 minutes),the time of uncinate process resection from left-side(the time from jejunum dissection to complete dissociation of the uncinate process) was 11.0(4.5) minutes(range:7.5 to 20.0 minutes),the time of pancreatic head resection (the time from jejunum dissection to pancreaticoduodenal specimen removal) was 26.0(8.5) minutes(range:20.0 to 41.0 minutes),the intraoperative blood loss was 200(150) ml(range:50 to 800 ml),and the intraoperative blood transfusion rate was 9.2% (14/152). Postoperative conditions:The postoperative hospital stay was 12 (9) d(range:6 to 55 d),the overall incidence of postoperative complications was 59.9%(91/152),and there was no perioperative death. Pathological results:The R0 resection rate of periampullary malignant tumor was 64.3%(77/112),with negative rate of uncinate process margin was 91.1%(102/112). The R0 resection rate of pancreatic ductal adenocarcinoma was 46.9%,with negative rate of uncinate process margin was 89.1%(57/64). Compared with the non-left-sided uncinate process first approach group(222.5(77.0) minutes, 9.2%(14/152)),the left-sided uncinate process first approach group had shorter operation time(246.0(94.0) minutes) (Z=3.964,P<0.01),less intraoperative blood loss (18.8%(22/117))(Z=4.843,P<0.01),and lower intraoperative blood transfusion rate(χ²=5.248,P=0.029). However,there were no significant differences between two groups in postoperative hospital stay(Z=1.682,P=0.093),postoperative overall complications(P=0.549),R0 resection rate of periampullary malignant tumor(χ²=2.012,P=0.156),and negative rate of uncinate process margin(χ²=2.108,P=0.147). Conclusions: The "left-sided uncinate process first approach" could completely resect uncinate process under a direct vision,especially when the uncinate process was behind the superior mesenteric artery or beyond the left lateral margin of the superior mesenteric artery. The "left-sided uncinate process first approach" might increase the negative rate of uncinate process margin and R0 resection rate for periampullary malignant tumor.

[Comparison of radical antegrade modular pancreatosplenectomy with conventional distal pancreatectomy for pancreatic adenocarcinoma of the body and tail].

Objective: To compare the short-term outcomes and long-term survivals of radical antegrade modular pancreatosplenectomy(RAMPS) and conventional distal pancreatectomy(CDP). Methods: A total of consecutive 304 patients including 176 male patients and 128 female patients who underwent RAMPS or CDP at Pancreas Center, the First Affiliated Hospital with Nanjing Medical University from May 2013 to June 2019 were retrospectively analyzed. The median age was 64.1 years old (range:39 to 85 years old). There were 101 patients underwent RAMPS and 203 patients underwent CDP. Measurement data with skewed distribution were presented as (M(Q(R))) and comparison between groups was evaluated with the Wilcoxon rank sum test. Count data were analyzed using the χ(2) test or Fisher exact probability. Survival analyses were performed by the Kaplan-Meier method after a one to one propensity score matching(PSM) conducted to balance several variables. Results: An eighty-one to eighty-one patients were enrolled after PSM. The overall morbidity was 32.1%(26/81)and there were no in-hospital mortalities in RAMPS. The median operative time was 225(95)minutes in RAMPS, not significantly longer as compared with CDP(210(130)minutes, P=0.916). The median greatest tumor diameter in RAMPS was 4.0(2.3)cm, not significantly larger as compared with CDP(4.5(2.2)cm, P=0.520).There were 34.6%(28/81)patients who presented with T4 tumors by 8(th) AJCC TNM staging system in RAMPS, which was not significantly different as compared with CDP(39.5%, χ(2)=0.574, P=0.902). The median number of examined lymph nodes was 9(9), not significantly greater in RAMPS as compared with CDP(10(11), P=0.992). The rate of negative posterior margins using 1 mm rule in RAMPS was 70.3%(52/74), significantly higher as compared with CDP(53.6%(30/56), χ(2)=3.817, P=0.044). The overall R0 resection rate was 44.6% (33/74) in RAMPS and 37.5% (21/56) in CDP, which was not significantly different(χ(2)=0.663, P=0.474). The median overall survival was 16.5 months for RAMPS, 25.2 months for CDP, and there was no statistical difference between two groups(P=0.981). The median overall survival was 16.0 months for patients with preoperative CA19-9≥300 U/ml who underwent RAMPS, 10.1 months for patients who underwent CDP, without significant difference(P=0.082). Conclusions: RAMPS can improve the rate of negative posterior margins by 1 mm rule and probably increase R0 resection rate and the harvest of lymph nodes. RAMPS may be beneficial to some patients with preoperative CA19-9≥300 U/ml.

[Analysis of risk factors and outcomes for delayed gastric emptying following pancreaticoduodenectomy: a single center experience of 492 cases].

Objective: To evaluate risk factors for delayed gastric emptying(DGE)following pancreaticoduodenectomy(PD). Methods: There were 492 consecutive patients who underwent PD in Pancreas Center, the First Affiliated Hospital with Nanjing Medical University between January 2012 and December 2014 were identified from a prospective database.There were 315 male and 177 female patients with a median age of 60.5 years.Univariate and multivariate analyses were performed to investigate the independent risk factors for clinically relevant DGE(CR-DGE). Results: The overall incidence of DGE was 29.5%, with Grade B and C occurring at 4.3% and 5.9%, respectively.In multivariate analysis, pancreatic duct diameter less than 3 mm(OR=1.888, P=0.042), pylorus-preserving pancreaticoduodenectomy(OR=2.627, P=0.005) and clinically relevant postoperative pancreatic fistula(OR=2.740, P=0.007) were independently associated with CR-DGE.Other main complications such as postoperative pancreatic fistula, pyoperitoneum, intraabdominal infection were also associated with the severity of DGE(χ(2)=21.360, 14.422, 14.378; P=0.011, 0.002, 0.002). DGE patients had a significantly prolonged postoperative length of stay(31(24-41)d vs. 13(11-17)d) and increased medical cost((122 367.5±66 068.3)yuan vs. (78 200.7±27 043.9)yuan)(both P<0.01). Conclusions: Small pancreatic duct, underwent pylorus-preserving pancreaticoduodenectomy and suffered postoperative pancreatic fistula might indicate a high risk of CR-DGE.

[Laparoscopic pancreaticoduodenectomy with a novel artery first and uncinate process first approach through Treitz ligament].

Objective: To explore the clinical effect of a novel artery first and uncinate process first approach for laparoscopic pancreaticoduodenectomy(LPD), emphasizing the left lateral and posterior dissection of uncinate process (UP) via Treitz ligament approach. Methods: From April to November 2016, 18 patients received LPD with a novel approach in Pancreas Center of the First Affiliated Hospital with Nanjing Medical University. All patients were diagnosed as pancreatic head or peri-ampulla tumor, without major vessel invasion nor distant metastasis. For resection, routine caudal view was used in the first step, to dissect the anterior medial border between uncinate process and superior mesenteric vein(SMV). Lymphatic tissues were completely dissected form anterior surface of hepatoduodenal ligament. In the second step, left lateral view with camera from left para-umbilical trocar was used, Treitz ligament was incised, SMA root was exposed. After anticlockwise rotation and retraction of mesentery, the anatomic relationship between SMA trunk, inferior pancreaticoduodenal artery(IPDA), jejunal branch of SMV, and distal part of UP, could be perfectly exposed from left lateral view. SMA was dissected from its root until the position above the uncinate process and duodenum, IPDA was transected, distal part of UP was freed from SMA. In the third step, right lateral view and caudal view were alternatively used; proximal UP mesentery was completely dissected out from SMA root, CA root and posterior surface of hepatoduodenal ligament. Pancreaticoduodenectomy was completed in the forth step after transection of pancreatic neck and common hepatic duct. Results: The SMA root and distal UP were successfully dissected out via Treitz ligament approach in all 18 patients, among them, distal UP was completely excised in 8 patients from left view. Postoperative pathology showed R0 resection rate in 69%. Postoperative complication included intra-abdominal hemorrhage in 1 patient, pancreatic fistula in 7 patients(6 cases with grade A and 1 case with grade B), delayed gastric emptying in 4 patients (2 cases with grade A, 2 cases with grade B). Average postoperative hospital stay was (15.5±6.8)days. Conclusion: The novel artery first and uncinate process first approach through Treitz ligament could help surgeons to completely dissect the full length of meso-pancreas along celiac axis-SMA axis in LPD.

Development of a novel high-entropy alloy with eminent efficiency of degrading azo dye solutions.

In addition to its scientific importance, the degradation of azo dyes is of practical significance from the perspective of environmental protection. Although encouraging progress has been made on developing degradation approaches and materials, it is still challenging to fully resolve this long-standing problem. Herein, we report that high entropy alloys, which have been emerging as a new class of metallic materials in the last decade, have excellent performance in degradation of azo dyes. In particular, the newly developed AlCoCrTiZn high-entropy alloy synthesized by mechanical alloying exhibits a prominent efficiency in degradation of the azo dye (Direct Blue 6: DB6), as high as that of the best metallic glass reported so far. The newly developed AlCoCrTiZn HEA powder has low activation energy barrier, i.e., 30 kJ/mol, for the degrading reaction and thus make the occurrence of reaction easier as compared with other materials such as the glassy Fe-based powders. The excellent capability of our high-entropy alloys in degrading azo dye is attributed to their unique atomic structure with severe lattice distortion, chemical composition effect, residual stress and high specific surface area. Our findings have important implications in developing novel high-entropy alloys for functional applications as catalyst materials.

An electronic criterion for assessing intrinsic brittleness of metallic glasses.

Bulk metallic glasses (BMGs) are characterized by a number of remarkable physical and mechanical properties. Unfortunately, these same materials are often intrinsically brittle, which limits their utility. Consequently, considerable effort has been expended searching for correlations between the phenomenologically complex mechanical properties of metallic glasses and more basic properties, such correlations might provide insight into the structure and bonding controlling the deformation properties of BMGs. While conducting such a search, we uncovered a weak correlation between a BMG's work function and its susceptibility to brittle behavior. We argue that the basis for this correlation is a consequence of a component of the work function - the surface dipole - and a fundamental bond property related to the shape of the charge density at a bond critical point. Together these observations suggest that simple first principle calculations might be useful in the search for tougher BMGs.

Designing novel bulk metallic glass composites with a high aluminum content.

The long-standing challenge for forming Al-based BMGs and their matrix composites with a critical size larger than 1 mm have not been answered over the past three decades. In this paper, we reported formation of a series of BMG matrix composites which contain a high Al content up to 55 at.%. These composites can be cast at extraordinarily low cooling rates, compatible with maximum rod diameters of over a centimetre in copper mold casting. Our results indicate that proper additions of transition element Fe which have a positive heat of mixing with the main constituents La and Ce can appreciably improve the formability of the BMG matrix composites by suppressing the precipitation of Al(La,Ce) phase resulted from occurrence of the phase separation. However, the optimum content of Fe addition is strongly dependant on the total amount of the Al content in the Al-(CoCu)-(La,Ce) alloys.

Depression in systemic lupus erythematosus patients is associated with link-polymorphism but not methylation status of the 5HTT promoter region.

A higher prevalence of depression in systemic lupus erythematosus (SLE) patients has been reported, though the mechanism underlying this phenomenon remains unclear. The present study was conducted to explore whether the polymorphism and methylation status of the serotonin transporter gene (5HTT) promoter region (PR-5HTT) contribute to depression in SLE patients from both genetic and epigenetic perspectives. In this study, 96 SLE patients and 96 healthy controls (HCs) were recruited. Depression levels of all subjects were evaluated using the Hamilton Depression Rating Scale (HDRS). The serotonin transporter-linked polymorphism (5HTTLPR) and the DNA methylation status of PR-5HTT were detected in peripheral lymphocytes of SLE patients and HCs. The differences in 5HTTLPR and DNA methylation of PR-5HTT between SLEs and HCs were compared. In SLE patients, the frequencies of short allele (S) and SS genotype of 5HTTLPR were higher in depressive SLE (SLE-D) patients than in non-depressive SLE (SLE-ND) patients. The mean HDRS score of SS homozygote patients was higher than that of patients with SL/LL genotypes. Conversely, PR-5HTT was hypomethylated in HCs as well as SLE patients. There was no difference in the methylation status between HCs and SLEs. Thus, the functional expression of PR-5HTT may be primarily regulated by gene polymorphism and not by DNA methylation. The risk allele of 5HTTLPR appears to be a major contributor to depression in SLE patients.

Enhancing glass-forming ability via frustration of nano-clustering in alloys with a high solvent content.

The glass-forming ability (GFA) of alloys with a high-solvent content such as soft magnetic Fe-based and Al-based alloys is usually limited due to strong formation of the solvent-based solid solution phase. Herein, we report that the GFA of soft magnetic Fe-based alloys (with >70 at.% Fe to ensure large saturation magnetization) could be dramatically improved by doping with only 0.3 at.% Cu which has a positive enthalpy of mixing with Fe. It was found that an appropriate Cu addition could enhance the liquid phase stability and crystallization resistance by destabilizing the α-Fe nano-clusters due to the necessity to redistribute the Cu atoms. However, excessive Cu doping would stimulate nucleation of the α-Fe nano-clusters due to the repulsive nature between the Fe and Cu atoms, thus deteriorating the GFA. Our findings provide new insights into understanding of glass formation in general.

Elastic moduli inheritance and the weakest link in bulk metallic glasses.

We show that a variety of bulk metallic glasses (BMGs) inherit their Young's modulus and shear modulus from the solvent components. This is attributed to preferential straining of locally solvent-rich configurations among tightly bonded atomic clusters, which constitute the weakest link in an amorphous structure. This aspect of inhomogeneous deformation, also revealed by our in situ neutron diffraction studies of an elastically deformed BMG, suggests a rubberlike viscoelastic behavior due to a hierarchy of atomic bonds in BMGs.

Ductilizing bulk metallic glass composite by tailoring stacking fault energy.

Martensitic transformation was successfully introduced to bulk metallic glasses as the reinforcement micromechanism. In this Letter, it was found that the twinning property of the reinforcing crystals can be dramatically improved by reducing the stacking fault energy through microalloying, which effectively alters the electron charge density redistribution on the slipping plane. The enhanced twinning propensity promotes the martensitic transformation of the reinforcing austenite and, consequently, improves plastic stability and the macroscopic tensile ductility. In addition, a general rule to identify effective microalloying elements based on their electronegativity and atomic size was proposed.

Metallic liquids and glasses: atomic order and global packing.

In this Letter, we have revealed the common structural behavior of metallic glasses through scrutinizing the evolution of pair distribution functions from metallic liquids to glasses and statistically analyzing pair distribution functions of 64 metallic glasses. It is found that the complex atomic configuration in metallic glasses can be interpreted globally as a combination of the spherical-periodic order and local translational symmetry. The implications of our study suggest that the glass transition could be visualized mainly as a process involving in local translational symmetry increased from the liquid to glassy states.

Hypermethylation of hepatic Gck promoter in ageing rats contributes to diabetogenic potential.

AIMS/HYPOTHESIS: Hepatic glucokinase (GCK) is a key enzyme in glucose utilisation. Downregulation of its activity is associated with insulin resistance and type 2 diabetes mellitus. However, it is unknown whether hepatic Gck expression is influenced by age and is involved in ageing-mediated diabetes, and whether the degree of methylation of the hepatic Gck promoter is correlated with the transcription of Gck. To address the question, we evaluated hepatic Gck transcription and promoter methylation in young (14 weeks), adult (40 weeks) and aged (80 weeks) rats. METHODS: Hepatic glycogen, Gck expression and the kinase activity of GCK were measured in three age groups. The CpG methylation status was determined by both bisulphite direct sequencing and clone sequencing of the PCR amplificates of Gck promoter. The causal relationship between Gck methylation and mRNA expression was confirmed by treating rat primary hepatocytes with 5-aza-2'-deoxycytidine (5-Aza-CdR). RESULTS: We have shown an age-associated decline in hepatic glycogen, Gck expression levels and the kinase activity of hepatic GCK. The eleven CpG sites studied displayed age-related progressive methylation changes in hepatic Gck promoter, which were confirmed by two methods: direct and clone sequencing. After 5-Aza-CdR treatment of rat primary hepatocytes, there was a fourfold increase in Gck expression. CONCLUSIONS/INTERPRETATION: Our results demonstrate that an age-related increase in methylation is negatively associated with hepatic Gck expression, suggesting that DNA methylation could be involved in increasing age-dependent susceptibility to hepatic insulin resistance and diabetes. Thus, the epigenetic modification of the hepatic Gck promoter may represent an important marker for diabetogenic potential during the ageing process.

Creep-resistant, Al2O3-forming austenitic stainless steels.

A family of inexpensive, Al2O3-forming, high-creep strength austenitic stainless steels has been developed. The alloys are based on Fe-20Ni-14Cr-2.5Al weight percent, with strengthening achieved through nanodispersions of NbC. These alloys offer the potential to substantially increase the operating temperatures of structural components and can be used under the aggressive oxidizing conditions encountered in energy-conversion systems. Protective Al2O3 scale formation was achieved with smaller amounts of aluminum in austenitic alloys than previously used, provided that the titanium and vanadium alloying additions frequently used for strengthening were eliminated. The smaller amounts of aluminum permitted stabilization of the austenitic matrix structure and made it possible to obtain excellent creep resistance. Creep-rupture lifetime exceeding 2000 hours at 750 degrees C and 100 megapascals in air, and resistance to oxidation in air with 10% water vapor at 650 degrees and 800 degrees C, were demonstrated.