In this paper, an improved voltage control strategy for microgrids (MG) is proposed, using an artificial neural network (ANN)-based adaptive proportional-integral (PI) controller combined with droop control and virtual impedance techniques (VIT). The control strategy is developed to improve voltage control, power sharing and total harmonic distortion (THD) reduction in the MG systems with renewable and distributed generation (DG) sources. The VIT is used to decouple active and reactive power, reduce negative power interactions between DG's and improve the robustness of the system under varying load and generation conditions. Simulation findings under different tests have shown significant improvements in performance and computational simulation. The rise time is reduced by 60%, the overshoot is reduced by 80%, the THD of the voltage is reduced by 75% (from 0.99 to 0.20%), and the THD of the current is reduced by 69% (from 10.73 to 3.36%) compared to the conventional PI controller technique. Furthermore, voltage and current THD values were maintained below the IEEE-519 standard limits of 5% and 8%, respectively, for the power quality enhancement. Fluctuations in voltage and frequency were also maintained at 2% tolerance and 1% tolerance, respectively, across all voltage limits, which is consistent with international norms. Power-sharing errors were reduced by 50% after conducting the robustness tests against the DC supply and load disturbances. In addition, the proposed strategy outperforms the previous control techniques presented at the state of the art in terms of adaptability, stability and, especially, the ability to reduce the THD, which validates its effectiveness for MG systems control and optimization under uncertain conditions.

• Klíčová slova
• AC microgrids, Adaptive PI controller, Artificial neural network, Distributed generators, Droop control, Total harmonic distortion reduction, Virtual impedance technique, Voltage regulation,
• Publikační typ
• časopisecké články MeSH

Amphoteric azo dyes were used for internal control of pI values in Comparative two-dimensional Fluorescence Gel Electrophoresis (CoFGE) [1]. The 2D-gel images of separated Escherichia coli proteins as well as those of colored amphoteric dyes separated by isoelectric focussing are presented. The latter were used to correct for variation in the first electrophoretic dimension and further improve protein coordinate assignment in 2D-gel electrophoresis. Data tables are supplied to demonstrate pI-value calibration and the effect on the assignment of protein spot coordinates.

• Klíčová slova
• 2D-PAGE, CoFGE, Gel electrophoresis, pI,
• Publikační typ
• časopisecké články MeSH

This example-oriented article addresses the computation of regions of all robustly relatively stabilizing Proportional-Integral (PI) controllers under various robust stability margins α for Linear Time-Invariant (LTI) plants with unstructured multiplicative uncertainty, where the plant model with multiplicative uncertainty is built on the basis of the second-order plant with three uncertain parameters. The applied graphical method, adopted from the authors' previous work, is grounded in finding the contour that is linked to the pairs of P-I coefficients marginally fulfilling the condition of robust relative stability expressed using the H∞ norm. The illustrative example in the current article emphasizes that the technique itself for plotting the boundary contour of robust relative stability needs to be combined with the precondition of the nominally stable feedback control system and with the line for which the integral parameter equals zero in order to get the final robust relative stability regions. The calculations of the robust relative stability regions for various robust stability margins α are followed by the demonstration of the control behavior for two selected controllers applied to a set of members from the family of plants.

• Klíčová slova
• H-Infinity norm, PI controllers, Robust control, Robust performance, Robust relative stability, Unstructured multiplicative uncertainty,
• Publikační typ
• časopisecké články MeSH

Cytokinetic membrane abscission is a spatially and temporally regulated process that requires ESCRT (endosomal sorting complexes required for transport)–dependent control of membrane remodeling at the midbody, a subcellular organelle that defines the cleavage site. Alteration of ESCRT function can lead to cataract, but the underlying mechanism and its relation to cytokinesis are unclear. We found a lens-specific cytokinetic process that required PI3K-C2α (phosphatidylinositol-4-phosphate 3-kinase catalytic subunit type 2α), its lipid product PI(3,4)P2 (phosphatidylinositol 3,4-bisphosphate), and the PI(3,4)P2–binding ESCRT-II subunit VPS36 (vacuolar protein-sorting-associated protein 36). Loss of each of these components led to impaired cytokinesis, triggering premature senescence in the lens of fish, mice, and humans. Thus, an evolutionarily conserved pathway underlies the cell type–specific control of cytokinesis that helps to prevent early onset cataract by protecting from senescence.

• MeSH
• biologická evoluce MeSH
• buněčné linie MeSH
• cytokineze * MeSH
• dánio pruhované MeSH
• endozomální třídící komplexy pro transport metabolismus   MeSH
• fosfatidylinositol-3-kinasy genetika   metabolismus   MeSH
• fosfatidylinositol-4,5-difosfát metabolismus   MeSH
• fosfatidylinositoly metabolismus   MeSH
• katarakta metabolismus   patologie   MeSH
• lidé MeSH
• mutace MeSH
• myši MeSH
• oční čočka cytologie   růst a vývoj   metabolismus   MeSH
• předčasné stárnutí MeSH
• proteiny buněčného cyklu metabolismus   MeSH
• proteiny dánia pruhovaného genetika   metabolismus   MeSH
• proteiny vázající vápník metabolismus   MeSH
• stárnutí buněk * MeSH
• tubulin metabolismus   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH
• Názvy látek
• CHMP4B protein, human MeSH Prohlížeč
• endozomální třídící komplexy pro transport MeSH
• fosfatidylinositol-4,5-difosfát MeSH
• fosfatidylinositoly MeSH
• PDCD6IP protein, human MeSH Prohlížeč
• phosphoinositide-3,4-bisphosphate MeSH Prohlížeč
• PIK3C2A protein, human MeSH Prohlížeč
• Pik3c2a protein, mouse MeSH Prohlížeč
• proteiny buněčného cyklu MeSH
• proteiny dánia pruhovaného MeSH
• proteiny vázající vápník MeSH
• tubulin MeSH
• VPS36 protein, human MeSH Prohlížeč

Growth factors and hormones activate global and selective protein translation by phosphorylation and therefore activation of p70 S6 kinase through a wortmannin-sensitive phosphoinositide-3 kinase (PI-3K) antiapoptotic pathway and a rapamycin-sensitive signalling pathway of mTOR. Here we demonstrate that the phosphorylation of 40S ribosomal protein S6, a physiological substrate p70 S6 kinase, was highly increased by growth-stimulation of the cytolytic T cells (CTLL2) with interleukin 2 (IL2), which was accompanied with the increased phosphorylation of p70 S6K. The activity of p70 S6K and phosphorylation of the S6 protein was completely blocked by rapamycin and significantly decreased upon treatment of the cells with wortmannin, indicating an involvement of the PI-3K pathway in concert with the signalling pathway of mTOR in IL2-dependent phos-phorylation of ribosomal protein S6. The phosphorylation and activity of PKB/Akt in IL2-stimulated CTLL2 cells were rapamycin-insensitive and reduced upon wortmannin treatment of the cells, confirming a requirement for PI-3K for Akt activity. The data support the hypothesis that Akt may act downstream to PI-3K and upstream to mTOR in an IL2-mediated signal transduction pathway that controls phosphorylation of the regulatory protein S6 in CTLL2 cells.

• MeSH
• androstadieny farmakologie   MeSH
• buněčné linie MeSH
• fosfatidylinositol-3-kinasy metabolismus   MeSH
• fosforylace * MeSH
• imunoblotting MeSH
• inhibitory enzymů farmakologie   MeSH
• interleukin-2 metabolismus   MeSH
• lidé MeSH
• myši MeSH
• protein-serin-threoninkinasy fyziologie   MeSH
• proteinkinasy metabolismus   MeSH
• protoonkogenní proteiny c-akt MeSH
• protoonkogenní proteiny * MeSH
• ribozomální protein S6 chemie   metabolismus   MeSH
• signální transdukce MeSH
• sirolimus farmakologie   MeSH
• TOR serin-threoninkinasy MeSH
• wortmannin MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• AKT1 protein, human MeSH Prohlížeč
• androstadieny MeSH
• inhibitory enzymů MeSH
• interleukin-2 MeSH
• MTOR protein, human MeSH Prohlížeč
• mTOR protein, mouse MeSH Prohlížeč
• protein-serin-threoninkinasy MeSH
• proteinkinasy MeSH
• protoonkogenní proteiny c-akt MeSH
• protoonkogenní proteiny * MeSH
• ribozomální protein S6 MeSH
• sirolimus MeSH
• TOR serin-threoninkinasy MeSH
• wortmannin MeSH

beta-catenin has a dual function; it is implicated in intercellular junctions and transcriptional co-activation. Here we examined the regulation of the expression and localization of beta-catenin in HT29 colorectal adenocarcinoma cells. Our results showed that inhibition of PI-3 kinase with wortmannin was accompanied by a considerably reduced expression of beta-catenin. This effect was overcome by butyrate and occurred at the protein level, not at the level of mRNA. Moreover, NaBT significantly increased the phosphorylation of the ribosomal protein, S6, known to participate in the translational control of gene expression. This was accompanied by the increased phosphorylation of p70 S6K and MAPKs, the effector proteins that are upstream of protein S6 in the distinct signaling pathways. These facts indicate that different signaling pathways may be involved in the regulation of beta-catenin synthesis. Modulation of beta-catenin expression induced by NaBT appeared to occur at the level of protein translation, suggesting that NaBT may act as a translational regulator.

• MeSH
• adenokarcinom metabolismus   MeSH
• alkalická fosfatasa metabolismus   MeSH
• androstadieny metabolismus   MeSH
• beta-katenin genetika   metabolismus   MeSH
• butyráty metabolismus   MeSH
• fosfatidylinositol-3-kinasy metabolismus   MeSH
• fosforylace MeSH
• imunohistochemie MeSH
• inhibitory fosfoinositid-3-kinasy MeSH
• kinasy ribozomálního proteinu S6, 70-kDa metabolismus   MeSH
• kinasy ribozomálního proteinu S6 metabolismus   MeSH
• kolorektální nádory metabolismus   MeSH
• lidé MeSH
• mitogenem aktivované proteinkinasy metabolismus   MeSH
• nádorové buněčné linie MeSH
• serin metabolismus   MeSH
• signální transdukce fyziologie   MeSH
• tyrosin metabolismus   MeSH
• wortmannin MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• alkalická fosfatasa MeSH
• androstadieny MeSH
• beta-katenin MeSH
• butyráty MeSH
• inhibitory fosfoinositid-3-kinasy MeSH
• kinasy ribozomálního proteinu S6, 70-kDa MeSH
• kinasy ribozomálního proteinu S6 MeSH
• mitogenem aktivované proteinkinasy MeSH
• serin MeSH
• tyrosin MeSH
• wortmannin MeSH

BACKGROUND: The PI*S variant is one of the most prevalent mutations within alpha-1 antitrypsin deficiency (AATD). The risk of developing AATD-related lung disease in individuals with the PI*SS genotype is poorly defined despite its substantial prevalence. Our study aimed to characterize this genotype and its risk for lung disease and compare it with the PI*ZZ and PI*SZ genotypes using data from the European Alpha-1 antitrypsin Deficiency Research Collaboration international registry. METHOD: Demographic, clinical, functional, and quality of life (QoL) parameters were assessed to compare the PI*SS characteristics with the PI*SZ and PI*ZZ controls. A propensity score with 1:3 nearest-neighbour matching was performed for the most important confounding variables. RESULTS: The study included 1007 individuals, with PI*SS (n = 56; 5.6%), PI*ZZ (n = 578; 57.4%) and PI*SZ (n = 373; 37.0%). The PI*SS population consisted of 58.9% men, with a mean age of 59.2 years and a mean FEV1(% predicted) of 83.4%. Compared to PI*ZZ individuals they had less frequent lung disease (71.4% vs. 82.2%, p = 0.037), COPD (41.4% vs. 60%, p = 0.002), and emphysema (23.2% vs. 51.9%, p < 0.001) and better preserved lung function, fewer exacerbations, lower level of dyspnoea, and better QoL. In contrast, no significant differences were found in the prevalence of lung diseases between PI*SS and PI*SZ, or lung function parameters, exacerbations, dyspnoea, or QoL. CONCLUSIONS: We found that, as expected, the risk of lung disease associated with the PI*SS genotype is significantly lower compared with PI*ZZ, but does not differ from that observed in PI*SZ individuals, despite having higher serum AAT levels. TRIAL REGISTRATION: www. CLINICALTRIALS: gov (ID: NCT04180319).

• Klíčová slova
• Alpha-1 antitrypsin, Lung disease, PI*SS, Registries,
• MeSH
• alfa-1-antitrypsin * genetika   MeSH
• deficit alfa1-antitrypsinu * genetika   epidemiologie   diagnóza   MeSH
• genotyp * MeSH
• kvalita života MeSH
• lidé středního věku MeSH
• lidé MeSH
• plicní nemoci genetika   epidemiologie   diagnóza   MeSH
• registrace MeSH
• rizikové faktory MeSH
• senioři MeSH
• Check Tag
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• multicentrická studie MeSH
• Názvy látek
• alfa-1-antitrypsin * MeSH
• SERPINA1 protein, human MeSH Prohlížeč

Precise pressure control in shell-and-tube steam condensers is crucial for ensuring efficiency in thermal power plants. However, traditional controllers (PI, PD, PID) struggle with nonlinearities and external disturbances, while classical tuning methods (Ziegler-Nichols, and Cohen-Coon) fail to provide optimal parameter selection. These challenges lead to slow response, high overshoot, and poor steady-state performance. To address these limitations, this study proposes a cascaded PI-PDN control strategy optimized using the electric eel foraging optimizer (EEFO). EEFO, inspired by the prey-seeking behavior of electric eels, efficiently tunes controller parameters, ensuring improved stability and precision. A comparative analysis against recent metaheuristic algorithms (SMA, GEO, KMA, QIO) demonstrates superior performance of EEFO in regulating condenser pressure. Additionally, validation against documented studies (CSA-based FOPID, RIME-based FOPID, GWO-based PI, GA-based PI) highlights its advantages over existing methods. Simulation results confirm that EEFO reduces settling time by 22.7%, overshoot by 78.7%, steady-state error by three orders of magnitude, and ITAE by 81.2% compared to metaheuristic based methods. The EEFO-based controller achieves faster convergence, enhanced robustness to disturbances, and precise tracking, making it a highly effective solution for real-world applications. These findings contribute to optimization-based control strategies in thermal power plants and open pathways for further bio-inspired control innovations.

• Klíčová slova
• Cascaded PI-PDN controller, Electric eel foraging optimizer, Metaheuristics, Nonlinear system, Pressure control, Steam condenser,
• Publikační typ
• časopisecké články MeSH

High-throughput mass spectrometry-based proteomic analysis requires peptide fractionation to simplify complex biological samples and increase proteome coverage. OFFGEL fractionation technology became a common method to separate peptides or proteins using isoelectric focusing in an immobilized pH gradient. However, the OFFGEL focusing process may be further optimized and controlled in terms of separation time and pI resolution. Here we evaluated OFFGEL technology to separate peptides from different samples in the presence of low-molecular-weight (LMW) color pI markers to visualize the focusing process. LMW color pI markers covering a large pH range were added to the peptide mixture before OFFGEL fractionation using a 24-wells device encompassing the pH range 3-10. We also explored the impact of LMW color pI markers on peptide fractionation labeled previously for iTRAQ. Then, fractionated peptides were separated by RP_HPLC prior to MS analysis using MALDI-TOF/TOF mass spectrometry in MS and MS/MS modes. Here we report the performance of the peptide focusing process in the presence of LMW color pI markers as on-line trackers during the OFFGEL process and the possibility to use them as pI controls for peptide focusing. This method improves the workflow for peptide fractionation in a bottom-up proteomic approach with or without iTRAQ labeling.

• Klíčová slova
• Low-molecular-weight color pI markers, Peptides OFFGEL fractionation, iTRAQ labeling,
• MeSH
• barva MeSH
• barvicí látky chemie   MeSH
• chemická frakcionace MeSH
• isoelektrická fokusace metody   MeSH
• koncentrace vodíkových iontů MeSH
• lidé MeSH
• molekulová hmotnost MeSH
• peptidy analýza   MeSH
• proteom analýza   MeSH
• sérový albumin analýza   MeSH
• tandemová hmotnostní spektrometrie metody   MeSH
• vysokoúčinná kapalinová chromatografie metody   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• barvicí látky MeSH
• peptidy MeSH
• proteom MeSH
• sérový albumin MeSH

The paper is focused on the computation of all possible robustly stabilizing Proportional-Integral-Derivative (PID) controllers for plants with interval uncertainty. The main idea of the proposed method is based on Tan's (et al.) technique for calculation of (nominally) stabilizing PI and PID controllers or robustly stabilizing PI controllers by means of plotting the stability boundary locus in either P-I plane or P-I-D space. Refinement of the existing method by consideration of 16 segment plants instead of 16 Kharitonov plants provides an elegant and efficient tool for finding all robustly stabilizing PID controllers for an interval system. The validity and relatively effortless application of presented theoretical concepts are demonstrated through a computation and simulation example in which the uncertain mathematical model of an experimental oblique wing aircraft is robustly stabilized.

• Klíčová slova
• Interval systems, Oblique wing aircraft, PI control, PID control, Robust stabilization,
• Publikační typ
• časopisecké články MeSH