Comparative Analysis of Preoperative Ratio Based Markers in Predicting Postoperative Infectious Complications After Gastrectomy

AIM

Postoperative infections (POIs) are associated with prolonged postoperative recovery, delayed adjuvant therapy, psychological problems, and poor long-term outcomes. The study aims to cross-compare the ratio-based preoperative parameters to predict POIs in patients with D2 gastrectomy for gastric cancer.

MATERIALS AND METHODS

A retrospective cohort and single-center study evaluated the data of 293 patients who underwent curative gastrectomy between January 2007 and November 2019 in a tertiary hospital in Istanbul. A receiver operating characteristic (ROC) curve was used to assess the ability of laboratory values to predict clinically relevant POIs. The predictive capacity of the neutrophil-lymphocyte ratio (NLR), lymphocyte-monocyte ratio (LMR), platelet-lymphocyte ratio (PLR), and CRP-albumin ratio (CAR) was calculated by the area under the curve. Then, the cutoff points were determined for all 4 indexes.

RESULTS

POIs developed in 77 (26.2%) patients. Patients with POI had higher Charlson comorbidity index (CCI) scores and a longer length of hospital stay. ROC curve analysis revealed that NLR, LMR, and CAR were significantly effective in predicting POI, while PLR was ineffective. LMR was the best ability to predict the POI. According to multivariate analysis, CCI score 3, NLR> 3.8, and LMR 2.34 were independent risk factors influencing the POI.

CONCLUSION

Preoperative LMR was most predictive for POI. Although CAR predicted the development of the POI, it was not superior to LMR and NLR. PLR did not have any prediction for POI. In addition, increased comorbidity (CCI 3) was an independent risk factor for POI.

New forward hadron calorimeter for centrality and reaction plane determination at BM@N heavy ion experiments

It is proposed to replace existing Zero Degree Calorimeter of the BM@N setup at the Nuclotron (JINR) by a new forward hadron calorimeter for the measurement of the collision centrality and reaction plane orientation in heavy ions experiments. This calorimeter with transverse and longitudinal segmentation will be assembled from modules presently constructed for FHCal MPD and PSD CBM. The proposed design of the new calorimeter, simulation results for centrality and reaction plane determination by the new calorimeter, as well as radiation doses in the calorimeter simulated by FLUKA are discussed. The performance of hadron calorimeter supermodule studied at CERN is shown.

The very forward hadron calorimeter PSD for the future CBM@FAIR experiment

The Projectile Spectator Detector (PSD) of the CBM experiment at the future FAIR facility is a compensating lead-scintillator calorimeter designed to measure the energy distribution of the forward going projectile nucleons and nuclei fragments (reaction spectators) produced close to the beam rapidity. The detector performance for the centrality and reaction plane determination is reviewed based on Monte-Carlo simulations of gold-gold collisions by means of four different heavy-ion event generators. The PSD energy resolution and the linearity of the response measured at CERN PS for the PSD supermodule consisting of 9 modules are presented. Predictions of the calorimeter radiation conditions at CBM and response measurement of one PSD module equipped with neutron irradiated MPPCs used for the light read out are discussed.

A nucleation and growth model of vertically-oriented carbon nanofibers or nanotubes by plasma-enhanced catalytic chemical vapor deposition

Carbon nanofibers are grown by direct current and hot filaments-activated catalytic chemical vapor deposition while varying the power of the hot filaments. Observations of these carbon nanofibers vertically oriented on a SiO2 (8 nm thick)/Si(100) substrate covered with Co nanoparticles (10-15 nm particle size) by Scanning Electron and Transmission Electron Microscopies show the presence of a graphitic "nest" either on the surface of the substrate or at the end of the specific nanofiber that does not encapsulate the catalytic particle. Strictly in our conditions, the activation by hot filaments is required to grow nanofibers with a C2H2 - H2 gas mixture, as large amounts of amorphous carbon cover the surface of the substrate without using hot filaments. From these observations as well as data of the literature, it is proposed that the nucleation of carbon nanofibers occurs through a complex process involving several steps: carbon concentration gradient starting from the catalytic carbon decomposition and diffusion from the surface of the catalytic nanoparticles exposed to the activated gas and promoted by energetic ionic species of the gas phase; subsequent graphitic condensation of a "nest" at the interface of the Co particle and substrate. The large concentration of highly reactive hydrogen radicals mainly provided by activation with hot filaments precludes further spreading out of this interfacial carbon nest over the entire surface of the substrate and thus selectively orientates the growth towards the condensation of graphene over facets that are perpendicular to the surface. Carbon nanofibers can then be grown within the well-known Vapor-Liquid-Solid process. Thus the effect of energetic ions and highly reactive neutrals like atomic hydrogen in the preferential etching of carbon on the edge of graphene shells and on the broadening of the carbon nanofiber is underlined.