Preparation and characterization of a chitosan-based low-pH-sensitive intelligent corrosion inhibitor

A chitosan （CS）-based low-pH-sensitive intelligent corrosion inhibitor was prepared by loading a pH-sensitive hydrogel with benzotriazole （BTA）; the pH-sensitive hydrogel was synthetized by crosslinking CS with glutaraldehyde （GTA）. Analysis by Fou- tier-transform inflared （FT-IR） spectroscopy showed that Schiff reactions occurred between amino and aldehyde groups. The swelling abil- ity of the hydrogel was investigated using a mass method, and it was observed to swell more in an acidic environment than in an alkaline en- vironment. The hydrogel＇s loading capacity of BTA was approximately 0.377 g·g ^-1, and its release speed was faster in an acidic environment than in an alkaline environment because of its swelling behavior. The corrosion inhibition ability of the intelligent inhibitor was tested by immersion and electrochemical methods. The results showed that after 4 h of immersion, the polarization resistance （Rp） value of copper with the intelligent inhibitor was approximately twice of that of copper with BTA, indicating that the intelligent inhibitor could effectively prevent copper from corroding.

Serum HER2 as a predictive biomarker for tissue HER2 status and prognosis in patients with gastric cancer

AIM To investigate the association between serum human epidermal growth factor receptor 2(HER2) extracellular domain(ECD) and tissue HER2 status, and the prognostic value of serum HER2 ECD in patients with gastric cancer.METHODS A total of 239 patients with gastric cancer were enrolled from December 2012 to June 2013. Serum HER2 ECD was determined by chemiluminescent assay, and tissue HER2 status was evaluated by immunohistochemistry and fluorescence in situ hybridization assay. A receiver operating characteristic(ROC) curve was plotted to identify the optimal cut-off value for serum HER2 ECD assay for predicting survival in gastric cancer patients.RESULTS Serum HER2 ECD was significantly correlated with tissue HER2 status(P < 0.001), tumor size(P < 0.001), and intestinal type of gastric cancer(P =0.021). Serum HER2 ECD levels differed significantly between patients with HER2-positive tissue expression and those with HER2-negative tissue expression. ROC analysis yielded an area under the curve value of 0.79(95%CI: 0.71-0.87, P < 0.001), with a sensitivity and specificity of 0.54(95%CI: 0.37-0.70) and 0.93(95%CI: 0.88-0.96), respectively. With a cut-off value of 24.75 ng/m L, high serum HER2 ECD had a negative impact on overall survival of the patients(HR: 1.93, 95%CI: 1.32-4.38, P = 0.006). CONCLUSION Serum HER2 ECD could be a highly specific surrogate biomarker for tissue HER2 status in gastric cancer. Optimal cut-off criteria for predicting survival should be established.

Could neoadjuvant chemotherapy increase postoperative complication risk of laparoscopic total gastrectomy? A monoinstitutional propensity score-matched study in China

The potential survival benefit of neoadjuvant chemotherapy(NC)in patients with advanced gastric cancer has been widely recognized.With the development of minimally invasive surgery,which is represented by laparoscopy,the effect of NC on the safety of laparoscopic gastrectomy remains to be further explored.AIM To compare the short-term outcomes of laparoscopic total gastrectomy(LTG)after NC(NC-LTG)with LTG alone.METHODS A total of 92 patients who underwent NC-LTG and 381 patients who received LTG alone at the Chinese PLA General Hospital between September 2015 and September 2020 were retrospectively included in our study.We used propensityscore matching(PSM)to balance baseline bias.After 1:1 PSM,73 patients were included in each group with no statistically significant difference in baseline characteristics.RESULTS The NC-LTG group exhibited a longer operation time(244.10±48.13 min vs 225.74±45.33 min,P=0.019)and increased intraoperative blood loss[150(100-300)mL vs 100(100-200)mL,P=0.011]compared to the LTG group.The 30-d postoperative morbidity of the NC-LTG group was 20.5%(15/73),and that of the LTG group was 13.7%(10/73).There were no significant differences in 30-d severe complication rates or anastomotic leakage rates.Subgroup analysis showed that the patients with pTNM(pathological tumor-node-metastasis classification)T0N0-II in the NC-LTG group underwent a longer operation than the LTG group,while no significant difference was found in any perioperative index for the pTNM III patients.A multivariate analysis showed that an operation time longer than 240 min was an independent risk factor(odds ratio=3.021,95%confidence interval:1.160-7.868,P=0.024),while NC was not an independent risk factor for postoperative complications in LTG.CONCLUSION Despite a longer operation time and more blood loss after NC-LTG,which indicate surgical difficulty,NC-LTG exhibits acceptable short-term outcomes compared to LTG,suggesting the safety and feasibility of NC-LTG.