The clinical outcomes of laparoscopic proximal gastrectomy with double-tract reconstruction versus tube-like stomach reconstruction in patients with adenocarcinoma of the esophagogastric junction based on propensity score-matching: a multicenter cohort study

PurposeLaparoscopic proximal gastrectomy with double-tract reconstruction (LPG-DTR) and laparoscopic proximal gastrectomy with tube-like stomach reconstruction (LPG-TLR) are both function-preserving procedures performed for treating AEG. However, there is no clinical consensus on the selection of digestive tract reconstruction after proximal gastrectomy, and the best way to reconstruct the digestive tract remains controversial. This study aimed at comparing the clinical outcomes of LPG-DTR and LPG-TLR to provide some reference to the choice of AEG surgical modalities.MethodsThis was a multicenter, retrospective cohort study. we collected clinicopathological and follow-up data of patients with consecutive cases diagnosed with AEG from January 2016 to June 2021 in five medical centers. According to the way of digestive tract reconstruction after tumor resection, patients who underwent LPG-DTR or LPG-TLR were included in the present study. Propensity score matching (PSM) was performed to balance baseline variables that might affect the study outcomes. The QOL of the patients was evaluated using the Visick grade.ResultsA total of 124 eligible consecutive cases were finally included. Patients in both groups were matched using the PSM method, and 55 patients from each group were included in the analysis after PSM. There was no statistically significant difference between the two groups in terms of the operation time, amount of intraoperative blood loss, days of postoperative abdominal drainage tube placement, postoperative hospitalization days, total hospitalization cost, the total number of lymph nodes cleared, and the number of positive lymph nodes (P>0.05). There was a statistically significant difference between the two groups in terms of time to first flatus after surgery and postoperative soft food recovery time (P<0.05). For the nutritional status, the weight levels at 1 year after surgery was better in the LPG-DTR group than in the LPG-TLR group (P<0.05). There was no significant difference in Visick grade between the two groups (P>0.05).ConclusionThe anti-reflux effect and quality of life of LPG-DTR for AEG were comparable to those of LPG-TLR. Compared with LPG-TLR, LPG-DTR provide better nutrition status for patients with AEG. LPG-DTR is a superior reconstruction method after proximal gastrectomy

Seismic response law of suspension bridge-track system of high-speed railway

Taking a suspension bridge of (84+84+1092+84+84) m high-speed railway as an example, a nonlinear dynamic simulation model of long-span suspension bridge-tracks system is established. The seismic response characteristics of CWR system of railway suspension bridge under the action of multi-dimensional seismic waves are analyzed. The effects of design parameters such as initial temperature load mode and viscous damper on the seismic response of the system are discussed. Calculation results showed that the longitudinal seismic excitation has great influence on the steel rail stress on the adjacent bridges on both sides and the longitudinal shear force at the pier bottom, and the transverse seismic excitation has great influence on the steel rail stress on the main truss of the suspension bridge, the vertical seismic excitation has a great influence on the internal forces of the main cable and sling; the initial temperature load has a significant influence on the internal forces of the main cable and sling; by reasonably setting the damping coefficient and speed index of the viscous damper, it can effectively reduce the displacement at the end of the main tower pier beam and the bending moment at the bottom of the pier

Natural product inspired chiral ligand design: Aloperine induced asymmetric hydroarylation of ketimines under Pd catalysed conditions

A naturally occurring alkaloid aloperine was utilized as a core chiral skeleton for the development of new ligands. Using these chiral 1,3-diamine ligands, a Pd catalysed asymmetric hydroarylation of ketimines was reported. A range of chiral sulfonyl amides were prepared in high yields and enantioselectivties. The stereoselectivity and structure relationships of aloperine has been studied by the introduction of various subsitituents. These discoveries would provide a new future development for natural product inspired chiral ligand design and developments

Microscopic pore structure of Chang 63 reservoir in Huaqing oilfield, Ordos Basin, China and its effect on water flooding characteristics

Abstract Chang 63 reservoir in Huaqing oilfield, Ordos Basin, China is featured by strong pore structure heterogeneity, which leads to prominent Jamin effect in the water flooding, difficult development process, low productivity, and massive residual oil. Accordingly, this study aims to explore the microscopic pore structure of Chang 63 reservoir and investigate its influence on the water flooding efficiency, based on a series of comprehensive analyses, including physical property analysis, casting thin section observation, scanning electron microscopy measurement, high-pressure mercury injection, constant rate mercury injection, and microscopic real sandstone water flooding model. It is demonstrated that gray and gray-brown feldspathic sandstone are the main reservoir lithology in the study area, with dominant pore types of residual intergranular pores and feldspar dissolution pores. Pore throat radius is unevenly distributed, and small and micro pores take the majority. Based on the comparison of capillary pressure curve characteristics and comprehensive analysis of corresponding parameters, the pore structure of the Chang 63 reservoir is divided into four types, namely types I–IV. They have different reservoir spaces, and their reservoir and seepage capacities decrease in the order of types I–IV pore structures. Moreover, displacement patterns in them are also different, with the finger-like-reticular displacement as the primary. In addition, pore throat radius and distribution play a critical role in the water flooding. It is also demonstrated that the water flooding efficiency increases with permeability and porosity, pore structure quality, and pore throat distribution evenness

Construction and in vitro evaluation of pH-sensitive nanoparticles to reverse drug resistance of breast cancer stem cells

Abstract Breast cancer is a major threat to safety and health of women. The breast cancer stem cells (BCSCs) have multi-drug resistance to chemotherapy drugs, which leads to chemotherapy failure. We proposed a strategy of delivery of tumor-killing drugs and a resistance reversal agent, to enhance inhibition of BCSCs. Here, schisandrin B (SchB)/AP NPs are constructed using acid-grafted-poly (β-amino ester) (ATRA-g-PBAE, AP) grafted polymer nanoparticle encapsulated SchB, with pH-sensitive release function. This drug delivery system has good pharmacological properties and can increase the SchB release with the decrease of pH. The NPs showed cytotoxic effects in reversing ATRA resistance to BCSCs. Lysosomal escape was achieved when the nanoparticles were taken up by BCSCs. In addition, we found that NPs may reverse MDR by inhibiting the expression of P-glycoprotein (P-gp) and affecting the energy supply of drug efflux. This study provides a nanodelivery therapy strategy that reverses BCSCs multidrug resistance (MDR) and demonstrates that it did so by interfering with cancer cell energy metabolism. Therefore, the co-delivery strategy of ATRA and SchB provides a new option for the treatment of breast cancer