Wideband Waveform Design for Distributed Precision Jamming.

Precision electronic warfare is a hot direction for future jamming technology development, and distributed precision jamming (DIPJ) is one of its typical application scenarios. The task objective of DIPJ is to design jamming waveforms so that the jamming energy generated by a set of ultra-sparse array transmitters can be focused in the jamming region of interest while being suppressed in other specific protected regions, which can be viewed as a distributed multiple-input and multiple-output system waveform design problem under a three-dimensional scenario. This paper extends the jamming signal model in DIPJ from narrowband to wideband based on previous work to address a broader range of jamming tasks. After extending the model to wideband signals, a method based on the traditional maximum total energy difference optimization objective is first given for comparison. A wideband jamming waveform design method based on the majorization minimization algorithm with the desired power spectrum matching as the optimization target is designed for the problem that the maximum energy difference method cannot focus energy well in the jamming region. The simulation results show that the presented method can make the jamming energy well concentrated in the target region and evenly distributed over the whole bandwidth, while the energy in the whole bandwidth is suppressed in the protected region.

Comparison of robotic and open pancreaticoduodenectomy for primary nonampullary duodenal adenocarcinoma: a retrospective cohort study.

PURPOSE: Robotic surgery has been increasingly applied in pancreatic surgery and showed many advantages over conventional open surgery. The robotic pancreaticoduodenectomy (RPD) is a surgical option for primary nonampullary duodenal adenocarcinoma (PNDA). However, whether RPD is superior to open pancreaticoduodenectomy (OPD) for PNDA has not been reported. The comparative study was designed to analyze the short- and long-term outcomes of RPD versus OPD on patients with PNDA. METHODS: Demographics, perioperative, and survival outcomes among patients who underwent RPD (n = 49) versus OPD (n = 43) for PNDAs between January 2013 and March 2018 were collected and analyzed RESULTS: Demographic characteristics were comparable between the RPD group and the OPD group. The RPD group demonstrated a decreased estimated blood loss (100 vs. 200 ml, p < 0.001), time to oral intake (4.0 vs. 4.0 days, p = 0.04), and postoperative hospital stay (12.9 vs. 15.0 days, p = 0.01) compared with the OPD group. However, no differences were observed between the two groups in terms of operative time and the rates of major complications, grade B and C POPF, PPH, grade B and C DGE, biliary fistular, reoperation, and 90-day readmission. No patient died within 90 days. There were no significant differences in tumor size, differentiation, TNM stage, number of harvested lymph nodes, and the rates of nerve invasion, lymph node invasion, R0 resection, and the median overall survival between the two groups (p > 0.05) CONCLUSIONS: RPD is a safe, feasible, and effective treatment for PNDA compared with OPD and can be used as an alternative for surgeons in the treatment of PNDA. Further multicenter randomized controlled trials are needed to evaluate the effectiveness of RPD in patients with PNDA.

Adjuvant nab-paclitaxel plus gemcitabine vs gemcitabine alone for resected pancreatic ductal adenocarcinoma: A single center experience in China.

BACKGROUND: Nab-paclitaxel plus gemcitabine (AG) has resulted in higher tumor response and survival rates for metastatic or advanced pancreatic ductal adenocarcinoma (PDAC) compared with gemcitabine (GEM) alone. AIM: To examine the feasibility and safety of AG adjuvant chemotherapy of resectable PDAC. METHODS: We retrospectively analyzed patients with resected PDAC who received AG or GEM as postoperative adjuvant treatment between January 2013 and December 2016 at the Chinese People's Liberation Army General Hospital, Beijing, China. The patients adopted combined nab-paclitaxel (125 mg/m2) and GEM (1 g/m2) or GEM (1 g/m2) alone treatment, on days 1 and 8 every 3 wk for six cycles, unless intolerable adverse events or disease progression occurred. The disease-free survival, overall survival (OS) and adverse events of the two groups were statistically analyzed. RESULTS: Compared with GEM, median disease-free survival (12.2 mo vs 15.8 mo, P = 0.039) and OS (20.6 mo vs 28.3 mo, P = 0.028) were significantly improved in the AG group. The 2-year OS rates were 63.3% and 43.3% in the AG and GEM groups, respectively. However, the incidence of sensory neuropathy was increased significantly in the AG than the GEM group (53.3% vs 23.3%, P < 0.001). CONCLUSION: In our initial experience, AG significantly improved disease-free survival and OS of patients with resected PDAC. AG may be a potential option for postoperative adjuvant chemotherapy of resectable PDAC.

Retrocolic versus antecolic gastrointestinal reconstruction in robotic pancreaticoduodenectomy.

BACKGROUND: With the advancement of robotic pancreaticoduodenectomy (RPD), several reconstruction methods have been advocated to make RPD more effective and safer. In this study, we investigated the safety and effectiveness of RPD using a left retrocolic (L-port) technique and compared it with those of RPD using an antecolic technique. METHODS: Between October 2015 and August 2016, we retrospectively reviewed consecutive cases of RPD before and after introducing the L-port technique for gastrointestinal reconstruction. The L-port technique was mainly performed for retrocolic gastrojejunal reconstruction and some cases of duodenojejunal reconstruction. The perioperative and postoperative outcomes were compared in the two groups. RESULTS: Eighty-three cases of RPD were retrieved for statistical analysis. Compared with the antecolic group, the L-port group was significantly associated with a shorter operative time (median time [IQR] 345 [307-384] min vs. 390 [370-455] min, P < 0.001), reconstruction time (54 [48-59] min vs. 84 [75-98] min, P < 0.001) and lower incidence of delayed gastric emptying. There were no cases of re-operation due to internal herniation, colonic ischemia, or bowel volvulus in the L-port group during the 1-year follow-up period. CONCLUSIONS: Our results demonstrated that the L-port technique of RPD is a safe and feasible technique for gastrointestinal reconstruction.

[A single-team experience with robotic pancreatic surgery in 1010 cases].

OBJECTIVE: To assess the safety and advantages of robotic pancreatic surgery (RPS) based on the single-team experience with 1010 cases. METHODS: The clinical data of 1010 cases of RPS performed by a single team from November, 2011 to September, 2017 in our hospital were collected prospectively and analyzed. In most of cases the surgeries were performed using the third-generation da Vinci robotic surgical system. RESULTS: The 1010 cases receiving RPS included 417 cases of robotic pancreatoduodenectomy (RPD), 428 cases of robotic distal pancreatectomy, 60 cases of robotic central pancreatectomy, 53 cases of robotic pancreatic tumor enucleation, 3 cases of Appleby procedure, and 49 cases of other operations (including 4 cases of innovative robotic retroperitoneal laparoscopic surgery, 4 cases of robotic pancreatic tumor enucleation combined with main pancreatic duct bridging repair, 1 case of single incision robotic pancreatic tumor enucleation, and 2 cases of robotic central pancreatectomy combined with end-to-end anastomosis reconstruction). The median operative time was 210 min (30-720 min) with a median intraoperative blood loss of 80 mL (10-2000 mL), a conversion rate of 4.06% (41/1010), a blood transfusion rate of 6.7% (68/1010), a mean post-operative stay of 10.87∓6.70 days, a complication rate (beyond grade III according to Clavien-Dindo scoring system) of 8.0% (81/1010), and a pancreatic fistula rate (beyond) grade B of 9.21% (93/1010). The mortality rate of the patients was 0.69% (7/1010) in 30 days and 1.31% (12//934) in 90 days. The application of RPS in total pancreatectomy increased steadily from the rate of 10.44% in 2012 to 72.06% in 2017. CONCLUSION: This represents to our knowledge the world largest series of robotic pancreatic resections. RPS is expected to gradually replace open procedure and laparoscopic procedure to become the primary choice of approach for pancreatectomy. After the learning curve, RPS procedure including distal pancreatectomy, robotic Appleby procedure and other operations can be safely performed, and the experiences from other centers can be beneficial to reduce severe complications in the early stage of learning.