Remarkable undercooling capability and metastable thermophysical properties of liquid Nb84.1Si15.9 alloy revealed by electrostatic levitation in outer space.

The stable manipulation, high undercooling, and thermophysical property measurement of the liquid Nb84.1Si15.9 refractory alloy were successfully achieved by the electrostatic levitation technique on board the China Space Station. By controlling the superheating temperature, a maximum liquid undercooling up to 421 K (0.18 TL) was obtained in the space environment, and two distinct solidification paths with different recalescence features were realized at metastable undercooled states. The liquid density and the ratio of specific heat to emissivity were measured in a wide temperature range from 1841 to 2346 K, which displayed linear and quadratic relations vs temperature, respectively. The liquid emissivity was further deduced from the specific heat of the liquid alloy calculated by molecular dynamics simulation. In addition, both the density and structural characteristics of the undercooled liquid alloy were also analyzed by MD calculations.

[Efficacy comparison between robot-assisted and laparoscopic surgery for mid-low rectal cancer: a prospective randomized controlled trial].

Objective: To compare the short- and long-term outcomes of robot-assisted and laparoscopic radical resection for mid-low rectal cancer. Methods: A prospective randomized controlled trial was conducted. A total of 130 patients with mid-low rectal cancer (inclusion criteria: age > 18 or ≤80 years old; pathological diagnosis of rectal adenocarcinoma by colonoscopy; distance from tumor to the anal verge ≤12 cm; no distant metastasis; cT1-3N0-1 or ycT1-3 after neoadjuvant radiotherapy and chemotherapy; suitable for laparoscopic and robotic surgery) at the Department of Colorectal Surgery of the First Affiliated Hospital of Nanchang University from October 2016 to September 2018 were prospectively enrolled. According to computer-generated random number method, patients were randomly divided into the robot group (n=66) and laparoscopy group (n=64), and underwent robot-assisted surgery or laparoscopic surgery respectively. Clinicopathological data of all the patients were collected and analyzed. The demographic parameters, short- and long-term outcomes were compared between two groups. Results: One patient in robot group whose postoperative sample was diagnosed as rectal adenoma by pathology was excluded. There were no statistically significant differences in age, sex, BMI, ASA classification, distance from tumor to the anal verge, serum CEA level, CA199 level between two groups (all P>0.05). Operations were successfully performed in all the patients without conversion to open operation. Robotic surgery was found to be associated with less intraoperative blood loss than laparoscopic surgery [(73.4±49.7) ml vs. (119.1±65.7) ml, t=-4.461, P<0.001], while there were no statistically significant differences in surgical procedures, operation time, time to first flatus, time to first liquid intake, time to removal of catheter or postoperative hospital stay between two groups (all P>0.05). Besides, there was no significant difference in the morbidity of postoperative complication between two groups [10.8% (7/65) vs. 12.5 (8/64), χ(2)=4.342, P=0.720]. The median number of harvested lymph node in the robot group and the laparoscopy group was 15.7±6.2 and 13.8±6.1 (t=1.724, P=0.087). There were no significant differences between two groups in tumor sample length, distance between proximal and distal resection margin, integrity grade of TME specimen, number of positive lymph nodes, postoperative pathological stage and tumor differentiation (all P>0.05). The distal resection margin of samples in two groups was all negative. One case in the robot group was found to have positive circumferential resection margin. The median follow up was 24 (9 to 31) months. In the robot group and the laparoscopy group, the 2-year overall survival rate was 95.4% and 90.6% respectively; the 2-year disease-free survival rate was 90.8% and 85.9% respectively, whose differences were not significant (both P>0.05). Conclusion: Robot-assisted radical resection for mid-low rectal cancer can achieve similar short-term and long-term outcomes of laparoscopic resection, while robot-assisted surgery can decrease blood loss during operation, leading to more precise practice in minimally invasive surgery.

[Key points and skills of assistant in robotic radical gastrectomy for gastric cancer].

An excellent assistant for robotic radical gastrectomy can play an important role in the operation, especially in a initial team. In robotic gastric cancer surgery, an excellent assistant should actively participate in the operation process, choose the appropriate trocar position according to patient's body habitus. Moreover, he should master various surgical instruments skillfully and switch instruments fluently to assist the surgeon to expose key parts during operation, and provide effective help in the operative details, so that the whole operation process can run more smoothly and the operation efficiency and quality will be greatly improved. The growth of the assistants needs constant practice and summary of experience. Meanwhile, the encouragement of the chief surgeon also plays a positive role in promoting the development of the assistants.

[Short-term clinical efficacy of robotic radical resection for high rectal cancer with transvaginal specimen extraction].

Objective: To explore the short-term clinical efficacy of robotic radical resection for high rectal cancer with transvaginal specimen extraction. Methods: A cohort study was carried out. The clinical data of consecutive patients with high rectal cancer who underwent robotic radical resection at the Department of General Surgery of The First Affiliated Hospital of Nanchang University from June 2017 to January 2018 were retrospectively analyzed. Inclusion criteria: (1) preoperative diagnosis of rectal cancer, and distance from tumor to anal margin≥10 cm undercolonoscopy; (2) T1-3 assessed by preoperative imaging examination, and no distant metastasis; (3) female, age≥50 years old, body mass index ≤ 30 kg/m(2); (4) without radiotherapy and chemotherapy before surgery; (5) implementation of robotic radical surgery for high rectal cancer. Fourteen female patients undergoing transvaginal removal of specimen without abdominal incision were included in the no incision group with age of (62.2±9.3) years old and distance from tumor to anal verge of (12.5±0.9) cm. As the match of 1:2, 28 simultaneous patients of high rectal cancer undergoing traditional robotic surgery (surgery interval <8 months) were enrolled to the control group, with age of (60.6±12.8) years old and distance from tumor to anal verge of (11.3±3.8) cm. Short-term efficacy and safty were compared between two groups. Follow-up ended in September 2018. Results: There was no significant difference in baseline data between the two groups (all P>0.05). Compared with the control group, the no incision group had longer operation time [(149.6±15.6) minutes vs. (130.9±12.9) minutes, t=-4.135, P<0.001], shorter time to postoperative flatus [(40.9 ±2.6) hours vs. (51.9±2.9) hours, t=12.049, P<0.001], lower pain score on the operation day and the first day after surgery (using Changhaipainstick) [(3.1±0.4) points vs. (4.6±0.7) points, t=7.458, P<0.001; (2.5±0.3) points vs. (3.3±0.5) points, t=6.142, P<0.001], shorter time to ground activity [(15.6±2.0) hours vs. (24.3±2.5) hours, t=11.102, P=0.030], and shorter postoperative hospital stay [(6.1±0.8) days vs. (7.2±1.3) days, t=2.806, P=0.008], whose differences were statistically significant. There were no significant differences in intraoperative blood loss, proportion of postoperative analgesia patients, and complication within 30 days after surgery (all P>0.05). In the no incision group and the control group,the tumor size was (3.1±0.4) cm and (3.6±0.9) cm, the proximal margin distance was (9.1±1.5) cm and (9.8±1.5) cm, the distal margin distance was (4.3±0.4) cm and (4.5±0.4) cm, the number of harvested lymph node was 15.8±2.4 and 15.2 ± 2.5, and the number of positive lymph node was 0.6±1.3 and 1.1±2.4, respectively, whose differences were not statistically significant (all P>0.05). The mean followed-up period was 10 months (7-14 months) in the no incision group, and 14 months (10-18 months) in the control group. No local recurrence and distant metastasis were found in both groups. Conclusion: Robotic radical resection for high rectal cancer with transvaginal specimen extraction is safe and feasible with advantages of rapid postoperative recovery, less postoperative pain and short hospital stay.

[Comparative study of clinical outcomes of robot versus laparoscopic radical surgery for rectal cancer based on propensity score matching].

Objective: To compare the short-term and long-term outcomes of robotic rectectomy and laparoscopic rectectomy for rectal cancer based on propensity score matching. Methods: The clinical data of 106 patients who underwent robotic or laparoscopic radical resection of rectal cancer at Department of General Surgery, the First Affiliated Hospital of Nanchang University from January 2015 to December 2015 were retrospectively collected. Propensity score matching method was used to perform 1∶1 matching between robot and laparoscopic rectal cancer radical surgery. Thirty-two patients in robot group and 32 patients in laparoscopic group were successfully matched. There were 15 males and 17 females in the robotic group, aging (56.2±7.5) years, 19 males and 13 females in the laparoscopic group, aged (55.5±7.6) years. The clinical outcome of the two groups were compared using t-test or Mann-Whitney U test for continuous variables, repeated measures analysis of variance, χ(2) test, Fisher exact test or Wilcoxon rank sum test for dichotomous variables. The overall survival curve was drawn by Kaplan-Meier curve and the difference of survival curve was compared by Log-rank method. Results: The general data of the two groups of patients were comparable after matching. Sixty-four patients successfully completed robotic or laparoscopic operation without conversion to open surgery or perioperative death case. The total operative time, the lymph node namely No. 253 group dissection time, intraoperative blood loss, postoperative urethral catheter retention time, the serum C-reactive protein levels of 24 hours after surgery were (135.7±12.1) minutes, (11.6±2.7) minutes, (66.8±10.2) ml, 3.0(1.0) d,(50.9±7.7) µg/L, respectively, while in laparoscopic group were (124.9±23.2) minutes, (13.2±2.7) minutes, (74.8±13.9) ml, 4.0(2.0) d, (55.9±6.7) µg/L respectively. The differences were statistically significant (t=2.341, t=-2.354, t=-2.621, Z=-2.743, F=7.902, respectively, P<0.05). There were no statistical differences in separation time, numbers of retrieved lymph nodes, time to first flatus, postoperative hospital stay, postoperative complication and Clavien-Dindo classification of postoperative complications (t=0.336, t=0.714, t=-0.568, Z=-1.766, Fisher Z=-0.586, respectively, all P>0.05). Conclusions: Robotic surgery not only has similar safety and feasibility but also has advantages of short-term outcomes compared with laparoscopic rectectomy for rectal cancer. The long-term outcomes were similar between two groups.

Identification of novel compound heterozygous RECQL4 mutations and prenatal diagnosis of Baller-Gerold syndrome: a case report.

Birth defects are structural and/or functional malformations present at birth that cause physical or mental disability and are important public health problems. Our study was aimed at genetic analysis and prenatal diagnosis of congenital anomalies to understand the cause of certain birth defects. Karyotypes and array-comparative genomic hybridization (aCGH) were performed on a pregnant woman, surrounding amniotic fluid, and her husband. A short-stature panel genetic test was conducted in accordance with the phenotype of the fetus. Following examination, it was determined that the karyotype and aCGH results were normal. The RECQL4 gene in the fetus showed compound heterozygous mutations, and each parent was found to be a carrier of one of the mutations. The two heterozygous mutations (c.2059-1G>C and c.2141_2142delAG) were detected in the RECQL4 (NM_004260) gene in the fetus; therefore, the fetus was predicted to have Baller-Gerold syndrome. These two mutations have not previously been reported. In addition, these results identified a 25% risk of the parents having a sec-ond conceptus with this congenital disease. Therefore, prenatal genetic diagnosis was highly recommended for future pregnancies.

Effects of bee venom peptidergic components on rat pain-related behaviors and inflammation.

To identify the active components of honeybee venom in production of inflammation and pain-related behaviors, five major peptidergic subfractions were separated, purified and identified from the whole honeybee venom. Among them, four active peptidergic components were characterized as apamin, mast-cell degranulating peptide (MCDP), phospholipase A(2) (PLA(2))-related peptide and melittin, respectively. All five subfractions were effective in production of local inflammatory responses (paw edema) in rats although the efficacies were different. Among the five identified subfractions, only MCDP, PLA(2)-related peptide and melittin were able to produce ongoing pain-related behaviors shown as paw flinches, while only apamin and melittin were potent to produce both thermal and mechanical hypersensitivity. As shown in our previous report, melittin was the most potent polypeptide in production of local inflammation as well as ongoing pain and hypersensitivity. To further explore the peripheral mechanisms underlying melittin-induced nociception and hypersensitivity, a single dose of capsazepine, a blocker of thermal nociceptor transient receptor potential vanilloid receptor 1, was treated s.c. prior to or after melittin administration. The results showed that both pre- and post-treatment of capsazepine could significantly prevent and suppress the melittin-induced ongoing nociceptive responses and thermal hypersensitivity, but were without influencing mechanical hypersensitivity. The present results suggest that the naturally occurring peptidergic substances of the whole honeybee venom have various pharmacological potencies to produce local inflammation, nociception and pain hypersensitivity in mammals, and among the five identified reverse-phase high pressure liquid chromatography subfractions (four polypeptides), melittin, a polypeptide occupying over 50% of the whole honeybee venom, plays a central role in production of local inflammation, nociception and hyperalgesia or allodynia following the experimental honeybee's sting. Peripheral transient receptor potential vanilloid receptor 1 is likely to be involved in melittin-produced ongoing pain and heat hyperalgesia, but not mechanical hyperalgesia, in rats.