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Polypropylene (PP)/clay nanocomposites (PPCNs) were autoclave-foamed in a batch process. Foaming was performed using supercritical 002 at 10 MPa, within the temperature range from 130.6[degrees] to 143.4[degrees]. i.e., below the melting temperature of either PPCNs or maleic anhydride-modified PP (PP-MA) matrix without clay. The foamed PP-MA and PPCN2 (prepared at 130.6[degrees]C and containing 2 wt% clay) show closed cell structures with pentagonal and/or hexagonal faces, while foams of PPCN4 and PPCN7.5 (prepared at 143.400, 4 and 7.5 wt% clay) had spherical cells. Scanning electron microscopy confirmed that foamed PPCNs had high cell density of [10.sup.7]-[10.sup.8] cells/mL, cell sizes in the range of 30-120 [mu]m, cell wall thicknesses of 5-15 [mu]m, and low densities of 0.05-0.3 g/mL. Interestingly, transmission electron microscopic observations of the PPCNs' cell structure showed biaxial flow-induced alignment of clay particles along the cell boundary. In this paper, the correlation between foam structure and reheological properties of the PPCNs is also discussed.

Reports on the autoclave-foam processing and cellular structure of polypropylene/clay nanocomposites. Maleic anhydride-modified polypropylene matrix without clay; Biaxial flow-induced alignment of clay particles; Uniaxial elongation flow.

Abstract: Layered polysilane (Si6H6) has a graphite-like structure with higher capacity than crystalline silicon. The rate of increase of the thickness of a layered polysilane electrode after 10 charge–discharge cycles was smaller than that for a Si powder electrode, although the layered polysilane electrode has higher capacity. The structural changes of electrochemically lithiated and delithiated layered polysilane at room temperature were studied using scanning electron microscopy, X-ray diffraction and Raman spectroscopy. Layered polysilane became amorphous by insertion of lithium to 0V, whereas insertion of lithium into crystalline silicon produces Li15Si4. Layered polysilane maintained an amorphous state during lithium insertion and deinsertion, whereas silicon changed between Li15Si4 and amorphous Li x Si, which explains the smaller volume change of a layered polysilane electrode compared with a Si powder electrode. [ABSTRACT FROM AUTHOR]

Postoperative pancreatic fistula (POPF) remains a major and serious problem after pancreaticoduodenectomy (PD). In its presence, pancreatic juice may leak from the main duct or branches of the pancreatic stump. To prevent this, we have applied a newly modified anastomosis of pancreaticogastrostomy (PG) using a linear stapler (stapled PG). Clinical records of 30 consecutive patients who underwent PD were reviewed between 2013 and 2023 at our community hospital. Regarding procedures, 12 stapled PGs and eighteen pancreaticojejunostomies (PJs) were performed after PD, from 2018 to 2023 and from 2013 to 2017, respectively. The pancreas was transected for long compression by a linear stapler, involving: pre-compression for 5 min, stapling for 5 min, and dissection for 5 min. After removal of the staples at the main duct opening of the pancreatic stump, PG anastomosis was performed. The outer layer was anastomosed by a straight single row pancreas-transfixing suture with the posterior gastric wall, and inner layer duct-to-mucosa anastomosis was also performed in a radial axis manner. Anastomosis of PJ was conducted without using a linear stapler. POPF was defined as a clinical manifestation of POPF (grade B/C) based on the ISGPF (International Study Group of Pancreatic Fistula) criteria. None of the 12 patients who had undergone stapled PG developed clinically relevant POPF, whereas 5 (27%) patients who had received PJ developed POPF. Three patients showed POPF grade B and 2 patients exhibited POPF grade C. Stapled PG after PD may reduce clinically relevant POPF. Because our sample size was small, the further accumulation of cases is required to validate this method., Competing Interests: The authors have no funding and conflict of interest to disclose., (Copyright © 2024 the Author(s). Published by Wolters Kluwer Health, Inc.)

Aim: To assess the clinical features of hepatoduodenal lymph node (HDLN) metastasis and to clarify the optimal indication of HDLN dissection., Methods: We investigated a total of 276 patients who underwent gastrectomy with extended lymphadenectomy, including HDLN dissection, for gastric cancer between 1999 and 2012. Of these, 26 patients (9.4%) had HDLN metastasis. First, we investigated the clinicopathological characteristics, their perioperative clinical outcomes, such as postoperative complications, and prognostic outcomes between patients with and without HDLN metastasis. Second, we detected the prognostic factors, particularly in patients with HDLN metastasis. Third, we assessed the therapeutic value of HDLN dissection to determine its optimal indication., Results: The five-year overall survival rate of the patients with HDLN metastasis was 29%. Univariate and multivariate logistic regression analyses revealed that the tumour location (the middle or lower stomach [P = 0.005, OR = 5.88 (95%CI: 1.61-38.1)] and pT category [T3 or T4, P = 0.017, OR = 4.45 (95%CI: 1.28-21.3)] were independent risk factors for HDLN metastasis. Cox proportional hazard analysis identified pN3 as an independent poor prognostic factor in the patients with HDLN metastasis [P = 0.021, HR = 5.17 (95%CI: 1.8-292)]. For patients who underwent radical HDLN dissection, HDLN metastasis was a prognostic indicator in pN3 gastric cancer (P < 0.0001), but not pN1-2 (P = 0.602). Furthermore, the index of therapeutic value of HDLN dissection for gastric cancer in the middle or lower stomach and the upper stomach was 3.4 and 0.0, respectively., Conclusion: We suggest that HDLN dissection should be indicated for pN1 or pN2 gastric cancers located at the middle or lower stomach.

Gastric carcinoma is derived from epithelial cells in the gastric mucosa. We reported an extremely rare case of submucosal gastric carcinoma originating from the heterotopic submucosal gastric gland (HSG) that was safely diagnosed by laparoscopy and endoscopy cooperative surgery (LECS). A 66-year-old man underwent gastrointestinal endoscopy, which detected a submucosal tumor (SMT) of 1.5 cm in diameter on the lesser-anterior wall of the upper gastric body. The tumor could not be diagnosed histologically, even by endoscopic ultrasound-guided fine-needle aspiration biopsy. Local resection by LECS was performed to confirm a diagnosis. Pathologically, the tumor was an intra-submucosal well differentiated adenocarcinoma invading 5000 μm into the submucosal layer. The resected tumor had negative lateral and vertical margins. Based on the Japanese treatment guidelines, additional laparoscopic proximal gastrectomy was curatively performed. LECS is a less invasive and safer approach for the diagnosis of SMT, even in submucosal gastric carcinoma originating from the HSG.

Aim: To allow the identification of high-risk postoperative pancreatic fistula (POPF) patients with special reference to the International Study Group on Pancreatic Fistula (ISGPF) classification., Methods: Between 1997 and 2010, 1341 consecutive patients underwent gastrectomy for gastric cancer at the Department of Digestive Surgery, Kyoto Prefectural University of Medicine, Japan. Based on the preoperative diagnosis, total or distal gastrectomy and sufficient lymphadenectomy was performed, mainly according to the Japanese guidelines for the treatment of gastric cancer. Of these, 35 patients (2.6%) were diagnosed with Grade B or C POPF according to the ISGPF classification and were treated intensively. The hospital records of these patients were reviewed retrospectively., Results: Of 35 patients with severe POPF, 17 (49%) and 18 (51%) patients were classified as Grade B and C POPF, respectively. From several clinical factors, the severity of POPF according to the ISGPF classification was significantly correlated with the duration of intensive POPF treatments (P = 0.035). Regarding the clinical factors to distinguish extremely severe POPF, older patients (P = 0.035, 65 years ≤ vs < 65 years old) and those with lower lymphocyte counts at the diagnosis of POPF (P = 0.007, < 1400/mm(3) vs 1400/mm(3) ≤) were significantly correlated with Grade C POPF, and a low lymphocyte count was an independent risk factor by multivariate analysis [P = 0.045, OR = 10.45 (95%CI: 1.050-104.1)]., Conclusion: Caution and intensive care are required for older POPF patients and those with lower lymphocyte counts at the diagnosis of POPF.