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Rheumatoid arthritis (RA) is a chronic inflammatory disease characterized by synovial inflammation and destruction of joint cartilage and bone. Different cytokines play important role in the processes that cause articular destruction and extra-articular manifestations in RA. The contribution of cytokines representing the Th1 (INF-γ), Th2 (IL-4) and IL-17A to the pathogenesis of early RA and bone mineral density (BMD) loss in still poorly understood. Serum samples of 38 early RA patients were evaluated for erythrocyte sedimentation rate (ESR), rheumatoid factor (RF), C-reactive protein (CRP), anti-cyclic citrullinated peptide antibodies (anti-CCP) and for the tested cytokines (IL-17A, IL-4 and INF-γ). BMD was evaluated by dualenergyX-ray absorptiometry (DXA). Disease activity score (DAS28) calculation was assessed for all patients. Control serum samples were obtained from 34 healthy volunteers. The levels of tested cytokines were significantly higher (IL-17A, p

We examine the impact of oil price uncertainty on IPO volume in the oil and gas sector. By using the implied volatility of oil options, a forward-looking uncertainty measure, we identify the effect of uncertainty on the going-public decision. Oil price uncertainty exhibits a strong negative relation to IPO volume. A one standard deviation decrease in the implied volatility results in a 29% increase in the number of quarterly IPOs. The effect is concentrated among the price-sensitive upstream producers. We further report that uncertainty positively impacts the IPO withdrawal decision and increases the value of postponing the offering. Keywords: Energy economics, IPOs, Implied crude oil volatility, Oil and gas sector, Oil price uncertainty, 1. INTRODUCTION Oil price uncertainty can affect both firms' investment and financing decisions. The impact of oil price uncertainty on investments in the oil and gas sector is well documented [...]

This study examines the impact of oil price uncertainty on mergers and acquisition (M&A) activity in the oil and gas sector. Analyzing this industry enables us to construct a natural forward-looking measure of oil price uncertainty, namely the implied crude oil volatility. Using a sample of U.S. firms in the oil and gas sector from 1994-2018 containing 4,323 announced transactions, we document that oil price uncertainty is negatively related to future M&A activity. Uncertainty is mainly a driver of horizontal and vertical M&A activity, where upstream firms are more affected by this uncertainty than downstream firms. Our results lend support to a real options explanation of investment under uncertainty where firms choose to defer investments as a response to increased uncertainty. Keywords: Energy economics, M&A, Corporate investment, Implied crude oil volatility, Oil and gas sector, Oil price uncertainty, 1. INTRODUCTION What is the impact of uncertainty on firms' investment activities, more specifically mergers and acquisitions (M&A)? Recent studies highlight the impact of political (Nguyen and Phan, 2017; Bonaime [...]

Abstract Background Vertebral fractures could lead to reduced physical, social and mental functioning, and loss of personal independence. Therefore, during the treatment of osteoporosis, it has become necessary to examine the changes in everyday functioning, well-being and health related quality of life (HRQOL). To that effect, this study aims to translate, culturally adapt, and validate the Serbian version of Quality of Life Questionnaire of the European Foundation for Osteoporosis (QUALEFFO-41) for patients with vertebral fractures. Methods Nine female patients with osteoporosis participated in the pre-validation study. A validation, case–control study included two groups of female patients: one that consisted of 50 female patients with osteoporosis, and with at least one vertebral fracture, and another one that consisted of 50 control patients with osteoporosis but without fractures. They completed the QUALEFFO-41 and the EuroQol group questionnaire with five dimensions (EQ-5D) twice within a month. The validation study examined internal consistency, concurrent validity, test-retest reliability, sensitivity and specificity. Results During the pre-validation study, three of the items in the QUALEFFO-41 were slightly changed. Afterwards, during the validation study, the statistically significant differences (adjusted for: age, duration of menopause, current employment and marital status) in the mean values of all domains and total scores between the groups were noted. For the case group, the internal consistency of the QUALEFFO-41 domains and of total questionnaire was above 0.70. The test-retest reliability was tested by the intraclass correlation coefficients (ICC) that were in range 0.87 – 0.96 for the case, and 0.15 – 0.83 for the control group. Correlations between the total scores of the QUALEFFO-41 and the EQ-5D health state value, for both groups were negative and statistically significant (r = -0.78, p Conclusions The Serbian QUALEFFO-41 version is reliable, valid, sensitive and predictive for examinations of HRQOL in patients with prevalent vertebral fractures and can be used in further studies.

Alginate hydrogels have gathered significant attention in biomedical engineering due to their remarkable biocompatibility, biodegradability, and ability to encapsulate cells and bioactive molecules, but much less has been reported on the kinetics of gelation. Scarce experimental data are available on cross-linked alginates (AL) with bioactive components. The present study addressed a novel method for defining the crosslinking mechanism using rheological measurements for aqueous mixtures of AL and calcium chloride (CaCl2) with the presence of hydroxyapatite (HAp) as filler particles. The time-dependent crosslinking behaviour of these mixtures was exploited using a plate–plate rheometer, when crosslinking occurs due to calcium ions (Ca2+) binding to the guluronic acid blocks within the AL polymer, forming a stable "egg-box" structure. To reveal the influence of HAp particles as filler on crosslinked sample morphology, after rheological measurement and crosslinking, crosslinked samples were freeze-dried and their morphology was assessed using an optical microscope and SEM. It was found that the addition of HAp particles, which are known to enhance the mechanical properties and biocompatibility of crosslinked AL gels, significantly decreased (usually rapidly) the interaction between the Ca2+ and AL chains. In this research, the physical "shielding" effect of HAp particles on the crosslinking of AL with Ca2+ ions has been observed for the first time, and its crosslinking behaviour was defined using rheological methods. After crosslinking and rheometer measurements, the samples were further evaluated for morphological properties and the observations were correlated with their dewatering properties. While the presence of HAp particles led to a slower crosslinking process and a more uniform development of the rheological parameters, it also led to a more uniform porosity and improved dewatering properties. The observed effects allow for a better understanding of the crosslinking process kinetics, which directly affects the physical and chemical properties of the AL gels. The shielding behaviour (retardation) of filler particles occurs when they physically or chemically block certain components in a mixture, delaying their interaction with other reactants. In hydrogel formulations, filler particles like hydroxyapatite (HAp) can act as barriers, adsorbing onto reactive components or creating physical separation, which slows the reaction rate and allows for controlled gelation or delayed crosslinking. This delayed reactivity is beneficial for precise control over the reaction timing, enabling the better manipulation of material properties such as crosslinking distribution, pore structure, and mechanical stability. In this research, the physical shielding effect of HAp particles was observed through changes in rheological properties during crosslinking and was dependent on the HAp concentration. The addition of HAp also enabled more uniform porosity and improved dewatering properties. The observed effects allow for a better understanding of the crosslinking process kinetics, which directly affects the physical and chemical properties of the AL gels. [ABSTRACT FROM AUTHOR]

This study proposes a reconfigurable open architecture control system for the Computer Numerical Control (CNC) woodworking educational machine tool called "EMCO F1 CNC". On this machine physical hardware reconfiguration (spindle position can be vertical and horizontal) is possible. The idea was to develop a control system that would follow the configuration changes of the machine tool. The educational character of the machine and its reconfigurability demand possibilities for machining programme simulations in order to determine optimal workpiece position in the workspace and programme verification. Those are the reasons for developing a virtual machine tool integrated with the control system as a digital twin. The study presents a novel methodology for the development of control systems, merging the concept of "virtual commissioning" with iterative error-driven processes. The objective was to develop a dynamic control system capable of promptly adjusting to kinematics changes in real time. In a wood machining experiment, a test workpiece for machine tools for both machine configurations verified the operation of the developed control system. [ABSTRACT FROM AUTHOR]

We investigated serum concentrations of specific inflammatory parameters in patients with significant carotid artery stenosis (CAS) of 50–99%, with an additional focus on patients with moderate stenosis (50–69%), in terms of both symptomatic status and plaque morphology, to determine whether there are certain parameters that can be associated with plaque instability before the progression of CAS to a high degree. The study included 119 CAS patients, 29 of whom had moderate stenosis, and 46 controls. Ultrasonography of the carotid arteries was performed using color flow Doppler and B-mode duplex ultrasound, and serum inflammatory parameters were measured using commercially available enzyme immunoassays. When comparing patients with 50–99% stenosis, only serum amyloid A (SAA) was higher in symptomatic patients, while in the group of patients with 50–69% stenosis, myeloperoxidase (MPO) was higher and pentraxin-3 (PTX-3) was lower in symptomatic compared to asymptomatic patients, and soluble urokinase plasminogen activator receptor (suPAR) was higher in patients with carotid plaque of unstable compared to stable morphology. Our results suggest that the importance of different inflammatory parameters in patients with moderate CAS is not the same as in CAS patients in general, and therefore their separate investigation in patients with high and moderate stenosis may be beneficial. SAA has the potential to be further considered in research to predict CAS symptom risk. There is a possibility that MPO and PTX-3 play a role in the development of CAS symptoms originating from less stenotic plaques and that suPAR is involved in the destabilisation of such plaques. [ABSTRACT FROM AUTHOR]

An advanced flexible programming methodology for CNC woodworking machines was developed. As the research starting base, a three-axis CNC woodworking machine was used. The developed methodology is proposed for programming, simulation, postprocessing, and machining by woodworking machine. This flexible programming method integrates the standard programming based on CAD, CAD/CAM systems, and STEP-NC protocol through different output files, enabling data interoperability during the realization of the machining tasks. The control system for the machine is configured based on the open-architecture software LinuxCNC to verify the flexible programming method and the results obtained. Programming verification was realized by simulation on a configured virtual machine in different programming environments and finally on a virtual machine integrated with the control system. The results obtained from the study were evaluated comparatively. [ABSTRACT FROM AUTHOR]

Sarcoidosis is an inflammatory condition that can affect multiple organ systems and is characterized by the formation of non-caseating granulomas in various organs, including the heart. Due to suboptimal diagnostic rates, the true prevalence and incidence of cardiac sarcoidosis (CS) remain to be determined. In patients with suspected CS, an initial examination should include 12-lead ECG or ambulatory ECG monitoring, and echocardiography with the estimation of LV, RV function, and strain rate. In patients with confirmed extracardiac sarcoidosis and with high clinical suspicion for CS, sophisticated imaging modalities, including cardiac MRI and PET, are indicated. Typical inflammation patterns and myocardial scarring should pose a high suspicion for CS. In patients without diagnosed extracardiac sarcoidosis and high clinical suspicion, although with low diagnostic probability, an endomyocardial biopsy should be considered to establish the diagnosis of definite isolated cardiac sarcoidosis. Timely diagnosis enables the initiation of therapy and close monitoring of adverse cardiac events that can be life-threatening, including sudden cardiac death, ventricular tachycardia, high-degree AV block, and heart failure. Implementing biomarkers in correlation to cardiac imaging can determine the disease's severity and progression but can also be helpful in following the treatment response. The formation of larger global registries can be helpful in the identification of independent predictors of adverse clinical events and the development of specific diagnostic algorithms to reduce the overall risk of this serious condition. [ABSTRACT FROM AUTHOR]