ON DESIGN OF SELF-TUNING ACTIVE FILTERS

In this paper, we present one approach in design of self-tuning all-pass, band-pass, low-pass and notch filters based on phase control loops with voltage-controlled active components and analyze their stability as well. The main idea is to vary signal delay of the filter and in this way to achieve phase correction. The filter phase characteristics are tuned by varying the transconductance of the operational transconductance amplifier or capacitance of an MOS varicap element, which are the constituents of filters. This approach allows us to implement active filters with capacitance values of order of pF, making the complete filter circuit to be amenable for realization in CMOS technology. The phase control loops are characterized by good controllable delay over the full range of phase and frequency regulation, high stability, and short settling (locking) time. The proposed circuits are suitable for implementation as a basic building RF function block, used in phase and frequency regulation, frequency synthesis, clock generation recovery, filtering, selective amplifying etc

Vascular complications in long COVID are very rare

Depending on the methodology thrombotic events during the acute COVID-19 infection were noted from 20 - 85%. Following the acute phase of the disease, it was noted that a subgroup of patients had various non-specific, prevailing symptoms for weeks, or even months and such a condition was accepted as a long COVID. Having in mind mechanisms of vascular complications in acute COVID infection and pathogenesis of long COVID, one would expect similar presentation and consequences of long COVID on human vasculature. We conducted a wide search of the literature on the topic and after screening of titles and abstracts papers with potential inclusion of the data regarding long COVID and vascular symptoms or complications that occurred during the time span of more than then 4 weeks after COVID infection. Research dealing with long COVID are mostly focused on symptoms and laboratory findings due to the nature of this condition. Data regarding vascular complications in these studies are either missing or the incidence of vascular complications was very low. Very few manifestations were related to cardiovascular system and D-dimer was assessed in only two studies showing increased values from very lot to almost in 30% of patients after COVID infection. Finally, in comparison of vascular complications with other viral infections in Sweden on patients undergoing diagnostic tests for venous thromboembolism increased risk for VTE in COVID-positive patients was proved. In the group of patients with chronic cardiovascular disease, the risk of arterial and venous thrombotic events after COVID infection is substantially higher. In comparison with seasonal influenza burden with coagulation disorders, pulmonary embolism, acute phlebitis, thrombophlebitis or thromboembolism and arterial embolism were higher and cumulative incidence was reported from 0.6 - 5.5% while hazard ration was from 2 - 18. Based on the published literature, vascular complications in the long COVID are very rare. Comparing to a very high rate of thrombotic events in the acute COVID infection and their correlation with severity of clinical presentation of COVID infection, the role and presence of vascular complications in long COVID is without any significance. Future studies focusing on the pathophysiology of long COVID could probably reveal potential mechanisms and explanations for such a difference

Monosomy 12 and deletion of 13q34 in a case of chronic lymphocytic leukemia with concomitant lung cancer

Background. We described a patient with chronic lymphocytic leukemia (CLL) and lung cancer and unusual chromosomal aberrations. Case report. At the same time with the diagnosis of B-cell CLL, squamocellular lung carcinoma diagnosis was established. Using interphase fluoresecence in situ hybridization technique (FISH) we detected monosomy 12 and deletion of 13q34 occured in the same clone. One month after the beginning of examination the patient died unexpectedly during sleep immediately before we applied a specific treatment for CLL or lung carcinoma. Conclusion. Simultaneous occurrence of monosomy 12 and deletion of 13q34 in a patient with B-cell CLL has been described only once before, but as a part of a complex karyotype. The prognostic significance of these abnormalities remains uncertain

IMPLEMENTATION OF MODERN INTELLIGENT CONTROL METHODS WITHIN THE CONTROL SYSTEMS STUDY MODULE

This paper presents an innovative project “Implementation of Modern Intelligent Control Methods within the Study Module Control Systems” which is selected to be financed by Serbian Ministry of Education, Science and Technological Development. The project is part of a public call for projects “Development of Higher Education” and it will be realized during a school year 2018/2019. In this paper, the main goals of the project are presented and project activities and expected results are defined. Finally, three courses which are selected to be innovated through the project activities are presented in the terms of lecture topics and teaching methods

SELF-TUNING LOW-NOISE AMPLIFIER

A low-noise amplifier with a phase control loop is described in this paper. In the proposed circuit, the resonant frequency is auto-tuned to the input signal frequency. In that way, high gain (20 dB), a phase shift of -180o between input and output signals, and good selective characteristics are obtained. The amplifier is robust to parameter variations, ensuring maximal amplification of the input signal regardless of its frequency as long as it is within a specified frequency range (880-950 MHz). Hence, the proposed circuit possesses self-tuning properties. The stability of the phase loop is analyzed by using Lyapunov's control theory

THE WINDER DANCER POSITION CONTROL MODEL USING DIFFERENT PID CONTROL STRUCTURES AND MICROLOGIX PLC

In the cable industry, improper regulation of the winding speed of the conductor cable, i.e. the position of the tensioner (dancer) leads to improper stretching of the conductor, which significantly affects the characteristics of the final product. Winding speed control is directly related to tensioning which is an additional problem. This paper presents a system for control a cable winding device using a linear PID controller with and without control signal limitation. The system parameters were determined using integral time-weighted absolute error (ITAE) criteria and realized using a conventional PLC controller

Clinical significance of TP53 aberrations and IGHV mutational status in chronic lymphocytic leukemia

Hronična limfocitna leukemija (HLL) izuzetno je heterogena bolest varijabilnog kliničkog toka. S jedne strane imamo, pacijente sa agresivnom i rezistentnom bolešću od koje umiru svega par meseci nakon dijagnoze, dok s druge strane spektra postoje pacijenti sa indolentnom, sporo progredirajućom bolešću koja ne zahteva lečenje decenijama. Razlozi su samo delimično poznati i već su decenijama unazad tema mnogobrojnih naučnih istraživanja. Tako je razvijen koncept prognostičkih i prediktivnih faktora u HLL-u, koji imaju za cilj da predvide klinički tok, odnosno terapijski ishod HLL-a. Liste prognostičkih i prediktivnih faktora su, sa boljim poznavanjem patofiziologije ove bolesti, svakom godinom sve duže, ali se i međusobno preklapaju. U ovom revijalnom radu izabrali smo aberacije TP53 gena i mutacioni status rearanžiranih IGHV (engl. immunoglobulin heavy variable) gena kao dva najznačajnija i najproučavanija faktora koji imaju i prognostički i prediktivni značaj.Chronic lymphocytic leukemia (CLL) is a very heterogeneous disease with a variable clinical course. On the one side of the spectrum, there are patients with aggressive and resistant disease, of which they die only a few months after diagnosis while, on the other side, there are patients with an indolent, slowly progressive disease that does not require treatment for decades. The reasons for this are only partially known, but they have been the subject of numerous scientific studies during the last several decades. Consequently, the concept of prognostic and predictive factors in CLL have emerged, which aims to predict the clinical course and its therapeutic outcome. With the improvement of understanding the pathophysiology of this disease, the lists of prognostic and predictive factors are getting longer every year, but they also overlap. In this review, we singled out the aberrations of the TP53 gene and the IGHV (immunoglobulin heavy variable) gene mutational status as the two most important and most studied factors that have both prognostic and predictive significance

Regulation of S100As Expression by Inflammatory Cytokines in Chronic Lymphocytic Leukemia

The calcium-binding proteins S100A4, S100A8, and S100A9 are upregulated in chronic lymphocytic leukemia (CLL), while the S100A9 promotes NF-κB activity during disease progression. The S100-protein family has been involved in several malignancies as mediators of inflammation and proliferation. The hypothesis of our study is that S100A proteins are mediators in signaling pathways associated with inflammation-induced proliferation, such as NF-κB, PI3K/AKT, and JAK/STAT. The mononuclear cells (MNCs) of CLL were treated with proinflammatory IL-6, anti-inflammatory IL-10 cytokines, inhibitors of JAK1/2, NF-κB, and PI3K signaling pathways, to evaluate S100A4, S100A8, S100A9, and S100A12 expression as well as NF-κB activation by qRT-PCR, immunocytochemistry, and immunoblotting. The quantity of S100A4, S100A8, and S100A9 positive cells (p < 0.05) and their protein expression (p < 0.01) were significantly decreased in MNCs of CLL patients compared to healthy controls. The S100A levels were generally increased in CD19+ cells compared to MNCs of CLL. The S100A4 gene expression was significantly stimulated (p < 0.05) by the inhibition of the PI3K/AKT signaling pathway in MNCs. IL-6 stimulated S100A4 and S100A8 protein expression, prevented by the NF-κB and JAK1/2 inhibitors. In contrast, IL-10 reduced S100A8, S100A9, and S100A12 protein expressions in MNCs of CLL. Moreover, IL-10 inhibited activation of NF-κB signaling (4-fold, p < 0.05). In conclusion, inflammation stimulated the S100A protein expression mediated via the proliferation-related signaling and balanced by the cytokines in CLL

Influence of applied CD34+ cell dose on the survival of Hodgkin's lymphoma and multiple myeloma patients following autologous stem cell transplants

Background/Aim. Autologous stem cell transplants (ASCTs) improve the rate of overall survival (OS) in patients with hematological malignancies such as multiple myeloma (MM) after induction chemotherapy, aggressive non-Hodgkin's lymphomas (NHL), and relapsed, chemotherapy-sensitive Hodgkin's lymphoma (HL). The study aim was to evaluate influence of applied CD34+ cell quantity on clinical outcome, as well as early post-transplant and overall survival (OS) of HL and MM patients following ASCT. Methods. This study included a total of 210 patients (90 HL/120 MM) who underwent ASCT. Stem cell (SC) mobilization was accomplished by granulocyte-colony stimulating factor (G-CSF) 10–16 μg/kg body mass (bm) following chemotherapy. For proven poor mobilizers, mobilization with G-CSF (16 μg/kgbm) and Plerixafor (24 or 48 mg) was performed. To our best knowledge, it was the first usage of the Plerixafor in our country in the ASCT-setting. Harvesting was initiated merely at "cut-off-value" of CD34+ cells ≥ 20 × 106/L in peripheral blood with "target-dose" of CD34+ cells ≥ 5 × 106/kgbm in harvest. The CD34+ cell count and viability was determined using flow cytometry. Results. The majority of HL patients (76.7%) were infused with > 5.0 × 106/kgbm CD34+ cells, while 68.3% of MM patients were treated by approximately 4.0–5.4 × 106/kgbm CD34+ dose, respectively. Beneficial response (complete/partial remission) was achieved in 83.3% (HL) and 94.2% (MM) patients. Among parameters that influenced survival of HL patients with positive response to the therapy, multivariate analysis (pre-ASCT performance status, CD34+ cell quantity applied, rapid hematopoietic, i.e. lymphocyte and platelet recovery) indicated that higher CD34+ cell dose used, along with pre-ASCT performance status correlated with superior event-free survival (EFS) and OS following ASCT. In MM patients, multivariate analysis (renal impairment, infused CD34+ cell quantity, early platelet recovery) indicated that the number of CD34+ cells infused was the most important parameter that influenced both EFS and OS after ASCT. Conclusion. Data obtained in this study undoubtedly confirmed that CD34+ cell dose applied is an independent factor that may contribute to superior clinical outcome and OS of HL and MM patients following ASCT