Microstructure, corrosion and wear properties of FeCrNiMo based coating produced on AISI 1040 steel by using laser coating technique

This study aims to investigate microstructure, hardness, corrosion and wear properties of FeCrNiMo-based coating produced on AISI 1040 steel by using laser welding method. Microstructure properties and phase formation were examined by SEM-EDS and XRD. The hardness measurement was made by using a microhardness device along a line from the upper surface of the coating to the substrate. The wear tests of both the substrate and coating layer were made with a scratch test device. SEM examinations showed that the coating layer had a dendritic microstructure and was uniformly bonded to the substrate. The coating layer was harder than the substrate. According to wear tests, the friction coefficient of the coating layer was lower compared to the substrate. Substrate and coating layer were immersed in an aqueous solution of %3,5 NaCl for potentiodynamic measurements. Corrosion results showed that coating of the AISI 1040 steel with FeCrNiMo increased the corrosion resistance

Wear properties and synthesis of CrFeNiMoTi high entropy alloy coatings produced by TIG process

659-664The aim of this study is to investigate wear and microstructure properties of CrFeNiMoTi high entropy alloy coating produced by using tungsten inert gas (TIG) process on the medium carbon steel. The coatings have been compared in terms of their phase composition, microstructure, and hardness. Phase compound and microstructure of coating layers have been examined by using X-ray diffractometer (XRD), scanning electron microscope (SEM), and optical microscope (OM). The images show that the coatings have consisted of the cladding zone, interface zone, and heat affected zone. Also, the microstructure of the coating has been mainly composed of dendrite and discontinuous interdendritic segregation. The surface microhardness of this high entropy alloys up to 450 HV0.3, has been about 2.5 times as the substrate. The wear behaviour of the specimens has been compared through dry sliding wear tests under the same conditions. Average coefficient of friction values of the high entropy alloy (HEA) coating has been obtained at relatively low levels

Wear properties and synthesis of CrFeNiMoTi high entropy alloy coatings produced by TIG process

The aim of this study is to investigate wear and microstructure properties of CrFeNiMoTi high entropy alloy coating produced by using tungsten inert gas (TIG) process on the medium carbon steel. The coatings have been compared in terms of their phase composition, microstructure, and hardness. Phase compound and microstructure of coating layers have been examined by using X-ray diffractometer (XRD), scanning electron microscope (SEM), and optical microscope (OM). The images show that the coatings have consisted of the cladding zone, interface zone, and heat affected zone. Also, the microstructure of the coating has been mainly composed of dendrite and discontinuous interdendritic segregation. The surface microhardness of this high entropy alloys up to 450 HV0.3, has been about 2.5 times as the substrate. The wear behaviour of the specimens has been compared through dry sliding wear tests under the same conditions. Average coefficient of friction values of the high entropy alloy (HEA) coating has been obtained at relatively low levels

Treatment of a Sequential Giant Fusiform Aneurysm of the Basilar Trunk

We report an exceptional case of a de novo giant fusiform aneurysm of the basilar trunk, which developed shortly after the therapeutic occlusion of the right internal carotid artery for a fusiform carotid aneurysm. It would appear to be appropriate to call this entity a sequential giant fusiform aneurysm. The patient was successfully treated with endovascular occlusion of the giant basilar trunk aneurysm following bypass surgery

Safety and Efficacy of the FRED Jr Flow Re-Direction Endoluminal Device for Intracranial Aneurysms: Retrospective Multicenter Experience With Emphasis on Midterm Results

Background and Purpose: Flow diversion is increasingly used as an endovascular treatment for intracranial aneurysms. In this retrospective multicenter study, we analyzed the safety and efficacy of the treatment of intracranial, unruptured, or previously treated but recanalized aneurysms using Flow Re-Direction Endoluminal Device (FRED) Jr with emphasis on midterm results. Materials and Methods: Clinical and radiological records of 150 patients harboring 159 aneurysms treated with FRED Jr at six centers between October 2014 and February 2020 were reviewed and consecutively included. Clinical outcome was measured by using the modified Rankin Scale (mRS). Anatomical results were assessed according to the O’Kelly-Marotta (OKM) scale and the Cekirge-Saatci Classification (CSC) scale. Results: The overall complication rate was 24/159 (16%). Thrombotic-ischemic events occurred in 18/159 treatments (11%). These resulted in long-term neurological sequelae in two patients (1%) with worsening from pre-treatment mRS 0–2 and mRS 4 after treatment. Complete or near-complete occlusion of the treated aneurysm according to the OKM scale was reached in 54% (85/158) at 6-month, in 68% (90/133) at 1-year, and in 83% (77/93) at 2-year follow-up, respectively. The rates of narrowing or occlusion of a vessel branch originating from the treated aneurysm according to the CSC scale were 11% (12/108) at 6-month, 20% (17/87) at 1-year, and 23% (13/57) at 2-year follow-up, respectively, with all cases being asymptomatic. Conclusions: In this retrospective multicenter study, FRED Jr was safe and effective in the midterm occlusion of cerebral aneurysms. Most importantly, it was associated with a high rate of good clinical outcome

Problems encountered in conventional HIV 1/2 Algorithms: lack of necessity for immunoblot assays to confirm repeated ELISA reactive results

Background: The use of conventional (serologically based) HIV 1/2 diagnostic algorithms has become controversial in recent years.Objectives: Sera from patients who underwent verification tests were evaluated because repeated ELISA-reactive results demonstrated a HIV1+HIV2 positive band pattern.Methods: The line immunoassay (LIA) test was used for repeated HIV enzyme immunoassays (EIA)-reactive sera in patients at three centers. The Bio-Rad Geenius™ HIV 1/2 and the HIV-1 RNA tests were used. HIV-1 and RNA HIV-2 were investigated using PCR.Results: LIA was used to evaluate 3,224 out of 10,591 samples with repeated ELISA reactivity (30%). We found that 32 (1%) of the sera, along with HIV1 bands and HIV2 gp36 bands, were positive. Only 28 of the 32 verified serum samples with gp36 bands were repeated, and no gp36 band positivity was detected using the Bio-Rad Geenius™ HIV-1/2 confirmatory assay in these serum samples. The HIV-2 proviral DNAs were also negative. Therefore, we excluded the possibility of HIV1+2 co-infection. All samples from the 32 patients were positive for HIV-1 RNA.Conclusion: Our findings highlight the need to exclude confirmatory tests like the LIA test from the current diagnostic HIV algorithm and replace it with rapid HIV-1 and HIV-2 confirmatory immunochromotographic tests.Keywords: HIV, AIDS, HIV-2