Comparison of the O-arm and C-arm guided pedicle screws placement

Background Transpedicular screw placement remains the gold standard technique for destabilization of the lumbar spine. Material and methods This is a retrospective study that analyzes patients that underwent the spinal stabilization surgical procedure. We compared results from two independent neurosurgical centers. At the turn of years 2012-2015, O-arm and StealthStation neuronavigation system was used for implantation of transpedicular screws. In 2018 to 2020 transcutaneous pedicle screw placement procedure was performed using standard C-arm device. Results In 208 procedures performed with the O-arm device, the accuracy of the positioning of the screws was 98.08 %. Screw repositioning was necessary in 1.92 % of all cases. In 30 procedures that were performed using the C-arm, the accuracy of the screws was 86.7% and the screw reposition procedure accounted for 10% (in one case crews were not replaced due to clinical sequelae). Conclusions Our data show that the spinal fusion with the O-arm tool has more accuracy, thus might be more indicated in procedures that require minimally invasive spinal stabilization

The application of 3D printing in neurosurgery: present and future

Background: For about 20 years we have been observing the development of three-dimensional (3D) printing. The aim of this study was to systematize the current knowledge on the use of 3D printing technology in neurosurgery and to aetmpt an outline the future paths of its development. Material and methods: The analysis was based on English-language literature from 2017-2021 indexed in the Mendeley and Scopus databases. Results: The application of 3D printing in neurosurgery concerns: 1) teaching students, 2) training of residents neurosurgeons, 3) individualized surgery planning, 4) dedicated cranial and spinal implants, 5) the future of 3D printing in neurosurgical implantology. There were 5 main neurosurgery subtopics in which 3D printing was used: “vascular neurosurgery” (31%), “skull, cranial neurosurgery” (22.4%), “neuro-oncology” (19.3%), “spine” (14.3%) and “others” (13%). The number of published articles has been steadily increasing by 11-33% annually. Conclusion: 3D printing has an enormous potential for clinical use and in the we will continue to observe its dynamic development. In neurosurgery 3D prints are currently most commonly used for didactic purposes as detailed anatomical models, for training residents and young surgeons and by specialists for the simulation of complex or innovative surgeries. The future of the use of additive 3D printing in neurosurgery lies in the biological 3D printing, the creation of artifcial organs and the development of biological implants in tissue engineering. Dzierżanowska N, Krakowiak M, Sokal P. The application of 3D printing in neurosurgery: present and future. Eur J Transl Clin Med. 2023;6(1):70-78

Experimental and numerical studies of rotating drum grate furnace

Waste material from the meat industry can be taken into account as a biofuel. Studies confirm, that calorific value is higher and ash content is lower comparing to some conventional fuels. EU directives regulate details of thermal disposal of the waste material from the meat industry - especially in range of the process temperature and time of the particle presence in area of the combustion zone. The paper describes design of the rotating drum grate stove, dedicated to thermal disposal of the meat wastes as well as solid biomass (pellet, small bricket, wood chips) combustion. Device has been developed in frames of cooperation between AGH University of Science and Technology (Krakow, Poland) and producer focused on technologies of energy utilization of biomass in distributed generation. Results of measurements of selected operational parameters performed during startup of the furnace have been presented and discussed. Furthermore, numerical model of the combustion process has been developed to complement experimental results in range of the temperature and oxygen distribution in the area of the combustion chamber. ANSYS CFX solver has been applied to perform simulations including rotational domain related with specifics of operation of the device. Results of numerical modelling and experimental studies have been summarized and compared

Assessment of the Possibility of Applying Ceramic Materials in Common Rail Injection Systems

Ceramic materials are currently interesting as substitutes for the metals traditionally used for engineering applications. This paper focuses on a comparison of ceramic materials: corundum (alumina, Al2O3) and silicon carbide (solid-state sintered) – SSiC with bearing alloy steel 100Cr6, i.e. the material used to make pistons and cylinders of pumps in common rail injection systems. The article is divided into two parts. In the first part, the aforementioned materials are characterized and their properties compared from the perspective of their application in piston-cylinder assemblies of injection pumps. The second part concerns analysis conduct by means of the finite element method and a specialized simulation environment, based on comparing ceramic materials and bearing steel. This comparison was conducted by using a CAD strength model of a piston in a specific application, being a pump with CP3 design. Simulation results confirmed the beneficial qualities of ceramic materials – the level of material deformation is lower for ceramics in comparison to steel

Understanding the origin of high corrosion inhibition efficiency of bee products towards aluminium alloys in alkaline environments

Ryl, Jacek/0000-0002-0247-3851; Krakowiak, Stefan/0000-0001-8192-8625; Niedzialkowski, Pawel/0000-0002-8197-6333; Ossowski, Tadeusz/0000-0002-0468-0133; Wysocka, Joanna/0000-0002-8016-9521WOS: 000461909000029Various bee products were found to be efficient corrosion inhibitors of aluminium in different environments. In particular, bee pollen was found to be highly effective in alkaline electrolytes, yet its highly complex composition and possible synergistic interactions hinder determination of the compounds acting as active corrosion inhibitors. The main purpose of the following work is to investigate the effect of solvents used for pollen extraction process on the corrosion inhibition of AA5754 alloy in alkaline environment. Both infrared and mass spectroscopies as well as chromatographic analysis were used to determine differences in the composition of each obtained extract. The inhibition efficiency (IE%) of each extract was determined by using the potentiodynamic polarization and impedance studies. The highest IE%, exceeding 90% at 10 gL(-1), was recorded for the water/ethanol extract. Most importantly, it has been found that the dichloromethane extract containing less polar compounds enhanced the corrosion rate at low bee pollen concentrations, and offered lower inhibition efficiency at the concentrations above 10 gL(-1). The adsorption isotherms were drawn based on dynamic impedance spectroscopy in galvanostatic mode (g-DEIS), while the measurements carried out at elevated temperatures allowed the construction of Arrhenius plots and, consequently, the confirmation of the physical mechanism of adsorption. (C) 2019 Elsevier Ltd. All rights reserved.Ministry of Science and Higher Education of PolandMinistry of Science and Higher Education, Poland [IP2015 067574]Authors acknowledge the financial support of the Ministry of Science and Higher Education of Poland from the budget funds in the period 2016-2019 under Iuventus Plus project IP2015 067574

Effects of Changes in Ownership of the Polish Hospital on the Patients’ Opinion About Its Functioning

System changes in health care centers have been directed at introducing such marketing elements into the Polish health care system as managerial approach to managing the centers and contracting medical services and quality management. High quality of the medical services and patients’ satisfaction became the key factors deciding about “the brand” of a health care center. The aim of the work was to assess the effect of changes in ownership of the hospital on the patients’ opinion about its functioning. Patients’ satisfaction survey was carried out through an anonymous questionnaire among 2702 respondents before and 2795 respondents after the transformation of the hospital. Multivariate analysis of variance (MANOVA) was used to analyze the collected empirical material. The assessment of the functioning of the admission center and hospital wards was significantly higher among the respondents asked after the transformation of the hospital as opposed to the assessment before it. Transforming the public hospital in Poland into a commercial company helped improve its functioning in the opinion of patients. There is a need to carry out further systematic research into the patients’ satisfaction better adjust the hospital’s offer to the needs of the hospitalized people

Sub-Perception and Supra-Perception Spinal Cord Stimulation in Chronic Pain Syndrome: A Randomized, Semi-Double-Blind, Crossover, Placebo-Controlled Trial

Background: The introduction of modern sub-perception modalities has improved the efficacy of spinal cord stimulation (SCS) in refractory pain syndromes of the trunk and lower limbs. The objective of this study was to evaluate the effectiveness of low and high frequency SCS among patients with chronic pain. Material and methods: A randomised, semi-double-blind, placebo controlled, four period (4 × 2 weeks) crossover trial was conducted from August 2018 to January 2020. Eighteen patients with SCS due to failed back surgery syndrome and/or complex regional pain syndrome were randomised to four treatment arms without washout periods: (1) low frequency (40-60 Hz), (2) 1 kHz, (3) clustered tonic, and (4) sham SCS (i.e., placebo). The primary outcome was pain scores measured by visual analogue scale (VAS) preoperatively and during subsequent treatment arms. Results: Pain scores (VAS) reported during the preoperative period was M (SD) = 8.13 (0.99). There was a 50% reduction in pain reported in the low frequency tonic treatment group (M (SD) = 4.18 (1.76)), a 37% reduction in the 1 kHz treatment group (M (SD) = 5.17 (1.4)), a 34% reduction in the clustered tonic settings group (M (SD) = 5.27 (1.33)), and a 34% reduction in the sham stimulation group (M (SD) = 5.42 (1.22)). The reduction in pain from the preoperative period to the treatment period was significant in each treatment group (p < 0.001). Overall, these reductions were of comparable magnitude between treatments. However, the modality most preferred by patients was low frequency (55% or 10 patients). Conclusions: The pain-relieving effects of SCS reached significance and were comparable across all modes of stimulation including sham. Sub-perception stimulation was not superior to supra-perception. SCS was characterised by a high degree of placebo effect. No evidence of carryover effect was observed between subsequent treatments. Contemporary neuromodulation procedures should be tailored to the individual preferences of patients

Factors Influencing the Opinion of Patients Concerning the Functioning of the Polish Hospital Before and After Ownership Transformation

Studies of satisfaction among patients are a popular and frequently obligatory tool used in improving the quality of medical services worldwide. Becoming familiar with the opinion of the patients enables to adjust the venue to their expectations, thus contributing to the increase in its competitiveness. We aimed to study patients’ satisfaction understood as a tool used in increasing the quality of medical services; in addition, we assessed factors that affect a worse review patients gave about the functioning of this Polish hospital before and after its transformation into a commercial company. The study of satisfaction among patients was conducted using an anonymous questionnaire among 2702 respondents before and 2795 respondents after the hospital’s transformation. Multivariate logistic regression analysis was applied to statistically analyze the collected empirical material, where the dependent variable was a worse evaluation of respondents concerning the functioning of the hospital. It was demonstrated that both before and after the hospital’s transformation into a commercial company, it was education and conditions of housing of patients that determined their opinion about the functioning of the admission center and hospital wards. A higher level of education increases the risk of a worse evaluation of the admission center and hospital wards, whereas higher self-evaluation of housing conditions lowered the discussed risk. Factors that influence the opinion of patients concerning the functioning of the hospital are education, age, marital status, housing conditions of the respondents and also the number of stays at a given hospital, and a conscious choice of the facility in which a patient wished to be treated

InterAtrial Shunt Device (IASD®) — nowa metoda inwazyjnego leczenia niewydolności serca z zachowaną frakcją wyrzutową lewej komory

Heart failure with preserved ejection fraction (HFpEF) is a condition with complex pathophysiology and clinical profile. No treatment has been proven to reduce mortality or reduce morbidity in a meaningful way. In the era of percutaneous cardiac interventions, a novel method of reducing left atrial pressure by creating an iatrogenic interatrial shunt has been introduced. We present a report of implantation of InterAtrial Shunt Device (IASD®) in three consecutive patients.Niewydolność serca z zachowaną frakcją wyrzutową lewej komory (HFpEF) jest stanem o złożonej patofizjologii i profilu klinicznym. Żadna z dotychczas proponowanych metod leczenia nie przyniosła efektu w zakresie redukcji zachorowalności i śmiertelności. W czasach ciągłego postępu inwazyjnych metod terapii chorób serca i naczyń zaproponowano metodę przezskórnego wytworzenia połączenia między przedsionkami w celu redukcji ciśnienia w lewym przedsionku. W niniejszej pracy zaprezentowano raport z implantacji urządzenia InterAtrial Shunt Device (IASD®) u trzech pacjentów