Correction: Bialobrzeska, B.; Jasinski, R. Resistance to Abrasive Wear with Regards to Mechanical Properties Using Low-Alloy Cast Steels Examined with the Use of a Dry Sand/Rubber Wheel Tester. Materials 2023, 16, 3052.

In the original publication [...].

Postoperative Hiatal Hernia after Ivor Lewis Esophagectomy-A Growing Problem in the Age of Minimally Invasive Surgery.

BACKGROUND: Even though minimally invasive esophagectomy is a safe and oncologically effective procedure, several authors have reported an increased risk of postoperative hiatal hernia (PHH). This study evaluates the incidence and risk factors of PHH after hybrid minimally invasive (HMIE) versus open esophagectomy (OE). METHODS: A retrospective single-center analysis was performed on patients who underwent Ivor Lewis esophagectomy between January 2009 and April 2018. Computed tomography scans and patient files were reviewed to identify the PHH. RESULTS: 306 patients were included (152 HMIE; 154 OE). Of these, 23 patients (8%) developed PHH. Most patients (13/23, 57%) were asymptomatic at the time of diagnosis and only 4 patients (17%) presented in an emergency setting with incarceration. The rate of PHH was significantly higher after HMIE compared to OE (13.8% vs. 1.3%, p < 0.001). No other risk factors for the development of PHH were identified in uni- or multi-variate analysis. Surgical repair of PHH was performed in 19/23 patients (83%). The recurrence rate of PHH after surgical repair was 32% (6/19 patients). CONCLUSIONS: The development of PHH is a relevant complication after hybrid minimally invasive esophagectomy. Although most patients are asymptomatic, surgical repair is recommended to avoid incarceration with potentially fatal outcomes. Innovative techniques for the prevention and repair of PHH are urgently needed.

Resistance to Abrasive Wear with Regards to Mechanical Properties Using Low-Alloy Cast Steels Examined with the Use of a Dry Sand/Rubber Wheel Tester.

This paper focuses on relationship between the mechanical properties and abrasive wear resistance, expressed by the Kb index, using an example of low-alloy cast steels. In order to achieve the aim of this work, eight cast steels of varying chemical composition were designed, cast and then heat treated. The heat treatment involved quenching and tempering at 200, 400 and 600 °C. Structural changes caused by tempering are demonstrated by the different morphologies of the carbide phases in the ferritic matrix. In the first part of this paper, the present state of knowledge about the influence of structure and hardness on the tribological properties of steels is discussed. This research involved the evaluation of a material's structure, as well as its tribological and mechanical properties. Microstructural observations were performed using a light microscope and a scanning electron microscope. Next, tribological tests were carried-out with the use of a dry sand/rubber wheel tester. To determine the mechanical properties, Brinell hardness measurements and a static tensile test were carried out. The relationship between the determined mechanical properties and abrasive wear resistance was then investigated. The analyses also provided information regarding the heat treatment states of the analyzed material in the as-cast and as-quenched states. It was found that the abrasive wear resistance, expressed by the index Kb, was most strongly correlated with hardness and yield point. In addition, observations of the wear surfaces indicated that the main wear mechanisms were microcutting and microplowing.

Austenite Grain Growth Analysis in a Welded Joint of High-Strength Martensitic Abrasion-Resistant Steel Hardox 450.

The paper presents the results of tests of a welded joint of Hardox 450 steel, belonging to the group of weldable high-strength boron steels with increased resistance to abrasive wear. As a result of the conducted research, apart from the basic structural indicators, an attempt was made to determine the correlation between the grain size of the prior austenite in the characteristic weld zones and its basic mechanical properties, such as yield point, tensile strength, percentage elongation after fracture, reduction of area, and impact strength. The scope of research quoted above was carried out for a welded joint of the considered steel at delivery state (directly after welding), in the normalising annealed state, as well as in water-quenched state, using different austenitisation temperatures in the range of 900-1200 °C. The results obtained showed a large influence of the parameters of the applied thermal heat treatment on the selected structural and mechanical properties of the welded joint.

Fractographic Analysis of Brinar 400 and Brinar 500 Steels in Impact Testing.

Properties of low-alloy boron-containing steels Brinar 400 and Brinar 500 in as-delivered and normalized conditions are considered. Charpy tests carried out within temperature ranges of ductile-to-brittle transition were followed by fractographic analysis. The tests were carried out on specimens with their axes parallel and perpendicular to hot-working direction, at -40°C, -20°C, 0°C, and +20°C. The determined impact properties of Brinar steels were complemented with fractographic analysis performed with use of a scanning electron microscope. It was found that temperatures of ductile-brittle transition were significantly different for the materials in as-delivered and normalized conditions. In addition the tensile tests were carried out, determining basic strength properties of the analyzed materials.

Effects of the nitric oxide donor JS-K on the blood-tumor barrier and on orthotopic U87 rat gliomas assessed by MRI.

Nitric oxide (NO) released from NO donors can be cytotoxic in tumor cells and can enhance the transport of drugs into brain tumors by altering blood-tumor barrier permeability. The NO donor JS-K [O(2)-(2,4-dinitrophenyl) 1-[(4-ethoxycarbonyl)piperazin-1-yl]diazen-1-ium-1,2-diolate] releases NO upon enzymatic activation selectively in cells overexpressing glutathione-S-transferases (GSTs) such as gliomas. Thus, JS-K-dependent NO effects - especially on cell viability and vascular permeability - were investigated in U87 glioma cells in vitro and in an orthotopic U87 xenograft model in vivo by magnetic resonance imaging (MRI). In vitro experiments showed dose-dependent antiproliferative and cytotoxic effects in U87 cells. In addition, treatment of U87 cells with JS-K resulted in a dose-dependent activation of soluble guanylate cyclase and intracellular accumulation of cyclic guanosine monophosphate (cGMP) which was irreversibly inhibited by the selective inhibitor of soluble guanylate cyclase ODQ (1H-[1,2,4]oxadiazolo(4,3a)quinoxaline-1-one). Using dynamic contrast enhanced MRI (DCE-MRI) as a minimally invasive technique, we demonstrated for the first time a significant increase in the DCE-MRI read-out initial area under the concentration curve (iAUC60) indicating an acute increase in blood-tumor barrier permeability after i.v. treatment with JS-K. Repeated MR imaging of animals with intracranial U87 gliomas under treatment with JS-K (3.5 µmol/kg JS-K 3×/week) and of untreated controls on day 12 and 19 after tumor inoculation revealed no significant changes in tumor growth, edema formation or tumor perfusion. Immunohistochemical workup of the brains showed a significant antiproliferative effect of JS-K in the gliomas. Taken together, in vitro and in vivo data suggest that JS-K has antiproliferative effects in U87 gliomas and opens the blood-tumor barrier by activation of the NO/cGMP signaling pathway. This might be a novel approach to facilitate entry of therapeutic drugs into brain tumors. DCE-MRI is a non-invasive, repeatable imaging modality to monitor biological effects of NO donors and other experimental therapeutics in intracranial tumor models.