Power parameters calculations based on wavelet packet transform

Power and power quality are of most importance in modern energy systems. The traditional method for power measurement and calculation uses Fourier transform. With Fourier transforms power calculations are performed in the time and frequency domains. However, it requires suitable windowing functions along with lengthy and complex (trigonometrically, exponentially, etc.) operations. In this study, a new approach which based on wavelet packet transform for power calculations of both fundamental and all harmonics of signals is proposed. The method is fast, efficient and overcomes limitations of the current techniques as mentioned above. The accuracy of the derived analytical equations is demonstrated via simulations implemented with the designed graphical user interface program and experimental works.     

Absence of basement membranes after targeting the LAMC1 gene results in embryonic lethality due to failure of endoderm differentiation

Centrosome duplication and separation are of central importance for cell division. Here we provide a detailed account of this dynamic process in Dictyostelium. Centrosome behavior was monitored in living cells using a gamma-tubulin-green fluorescent protein construct and correlated with morphological changes at the ultrastructural level. All aspects of the duplication and separation process of this centrosome are unusual when compared with, e.g., vertebrate cells. In interphase the Dictyostelium centrosome is a box-shaped structure comprised of three major layers, surrounded by an amorphous corona from which microtubules emerge. Structural duplication takes place during prophase, as opposed to G1/S in vertebrate cells. The three layers of the box-shaped core structure increase in size. The surrounding corona is lost, an event accompanied by a decrease in signal intensity of gamma-tubulin-green fluorescent protein at the centrosome and the breakdown of the interphase microtubule system. At the prophase/prometaphase transition the separation into two mitotic centrosomes takes place via an intriguing lengthwise splitting process where the two outer layers of the prophase centrosome peel away from each other and become the mitotic centrosomes. Spindle microtubules are now nucleated from surfaces that previously were buried inside the interphase centrosome. Finally, at the end of telophase, the mitotic centrosomes fold in such a way that the microtubule-nucleating surface remains on the outside of the organelle. Thus in each cell cycle the centrosome undergoes an apparent inside-out/outside-in reversal of its layered structure.     

Determination of metals in fish species from Aegean and Mediterranean seas

Determination of metal levels in muscles and livers of twelve fish species from Aegean Sea and Mediterranean Sea by ICP-AES was made. The levels of Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn in muscles of fish were <0.01–0.39, <0.01–0.45, 0.07–1.48, 0.51–7.05, 9.18–136, 0.18–2.78, 0.03–1.72, 0.21–1.28 and 3.51–53.5 mg kg⁻¹, respectively. Metal levels in muscles were generally lower than those in livers. Metal concentrations in the edible parts of fish were assessed for human uses according to provisional tolerable weekly intake (PTWI) and provisional tolerable daily intake (PTDI). The estimated values of all metals in muscles of fish in this study were below the established values. Therefore, it can be concluded that these metals in edible parts of the examined species should pose no health problems for consumers.     

Detection and frequency of VT1, VT2 and eaeA genes in Escherichia coli O157 and O157:H7 strains isolated from cattle, cattle carcasses and abattoir environment in Istanbul

The aim of this study was to detect VT1, VT2 and eaeA genes and to determine the frequency of these genes in Escherichia coli O157 and O157:H7 strains isolated from cattle, cattle carcasses and environmental samples of the 5 abattoirs located in Istanbul, Turkey. For this, the presence of VT1, VT2 and eaeA genes in 26 strains of E. coli O157:H7 and 6 strains of O157 was investigated by multiplex-PCR. The results have shown that eaeA gene was detected in all O157 and O157:H7 strains tested. Both VT2 and eaeA genes were detected in 4 (80%) of 5 strains of E. coli O157 and eaeA alone in 1 strain of O157. In 27 strains of O157:H7, 5 (18.5%) strains were found to be positive for VT1, VT2 and eaeA genes, 19 (70.3%) strains for both VT2 and eaeA and, 3 (11.1%) strains for only eaeA gene. Either VT1 alone or VT2 alone was not detected in any strains tested. eaeA gene alone in 2 strains, VT2-eaeA genes in 9 strains and VT1-VT2-eaeA genes in 2 strains were detected in 13 of E. coli O157:H7 strains isolated from cattle. eaeA alone in 1 strain, VT2-eaeA genes in 5 strains and VT1-VT2-eaeA genes in 2 strains were detected in 8 of E. coli O157:H7 strains isolated from carcasses. VT2-eaeA genes in 5 strains (isolated from hands, apron, knife and floor) and VT1-VT2-eaeA genes in 1 strain (isolated from knife) were also detected in 6 of E. coli O157:H7 strains isolated from environmental samples. This study reveals that most of the strains are found to be toxigenic and it is most likely that strains isolated from carcasses and abattoir environment originated from cattle feces. Therefore, HACCP systems are necessary from farm to table especially in the abattoirs to prevent contamination of meat and abattoir environment with intestinal content.     

Effects of Chronic Kidney Disease on Nanomechanics of the Endothelial Glycocalyx Are Mediated by the Mineralocorticoid Receptor

Endothelial mechanics control vascular reactivity and are regulated by the mineralocorticoid receptor (MR) and its downstream target, the epithelial Na⁺ channel (ENaC). Endothelial dysfunction is a hallmark of chronic kidney disease (CKD), but its mechanisms are poorly understood. We hypothesized that CKD disrupts endothelial mechanics in an MR/ENaC-dependent process. Methods: Primary human endothelial cells were cultured with uremic serum derived from children with stage 3–5 (predialysis) CKD or adult hemodialysis (HD) patients or healthy controls. The height and stiffness of the endothelial glycocalyx (eGC) and cortex were monitored by atomic force microscopy (AFM) using an ultrasensitive mechanical nanosensor. Results: In a stage-dependent manner, sera from children with CKD induced a significant increase in eGC and cortex stiffness and an incremental reduction of the eGC height. AFM measurements were significantly associated with individual pulse wave velocity and serum concentrations of gut-derived uremic toxins. Serum from HD patients increased MR expression and mechanical stiffness of the endothelial cortex, an effect reversed by MR and ENaC antagonists, decreased eNOS expression and NO bioavailability, and augmented monocyte adhesion. Conclusion: These data indicate progressive structural damage of the endothelial surface with diminishing kidney function and identify the MR as a mediator of CKD-induced endothelial dysfunction.     

Epidermal Growth Factor Stimulates Extracellular-Signal Regulated Kinase Phosphorylation of a Novel Site on Cytoplasmic Dynein Intermediate Chain 2

Extracellular-signal regulated kinase (ERK) signaling is required for a multitude of physiological and patho-physiological processes. However, the identities of the proteins that ERK phosphorylates to elicit these responses are incompletely known. Using an affinity purification methodology of general utility, here we identify cytoplasmic dynein intermediate chain 2 (DYNC1I-2, IC-2) as a novel substrate for ERK following epidermal growth factor receptor stimulation of fibroblasts. IC-2 is a subunit of cytoplasmic dynein, a minus-end directed motor protein necessary for transport of diverse cargos along microtubules. Emerging data support the hypothesis that post-translational modification regulates dynein but the signaling mechanisms used are currently unknown. We find that ERK phosphorylates IC-2 on a novel, highly conserved Serine residue proximal to the binding site for the p150^Glued subunit of the cargo adapter dynactin. Surprisingly, neither constitutive phosphorylation nor a phosphomimetic substitution of this Serine influences binding of p150^Glued to IC-2. These data suggest that ERK phosphorylation of IC-2 regulates dynein function through mechanisms other than its interaction with dynactin.     

A Quick Route to Multiple Highly Potent SARS-CoV-2 Main Protease Inhibitors**

The COVID-19 pathogen, SARS-CoV-2, requires its main protease (SC2M^Pro) to digest two of its translated long polypeptides to form a number of mature proteins that are essential for viral replication and pathogenesis. Inhibition of this vital proteolytic process is effective in preventing the virus from replicating in infected cells and therefore provides a potential COVID-19 treatment option. Guided by previous medicinal chemistry studies about SARS-CoV-1 main protease (SC1M^Pro), we have designed and synthesized a series of SC2M^Pro inhibitors that contain β-(S-2-oxopyrrolidin-3-yl)-alaninal (Opal) for the formation of a reversible covalent bond with the SC2M^Pro active-site cysteine C145. All inhibitors display high potency with K_i values at or below 100 nM. The most potent compound, MPI3, has as a K_i value of 8.3 nM. Crystallographic analyses of SC2M^Pro bound to seven inhibitors indicated both formation of a covalent bond with C145 and structural rearrangement from the apoenzyme to accommodate the inhibitors. Virus inhibition assays revealed that several inhibitors have high potency in inhibiting the SARS-CoV-2-induced cytopathogenic effect in both Vero E6 and A549/ACE2 cells. Two inhibitors, MPI5 and MPI8, completely prevented the SARS-CoV-2-induced cytopathogenic effect in Vero E6 cells at 2.5–5 μM and A549/ACE2 cells at 0.16–0.31 μM. Their virus inhibition potency is much higher than that of some existing molecules that are under preclinical and clinical investigations for the treatment of COVID-19. Our study indicates that there is a large chemical space that needs to be explored for the development of SC2M^Pro inhibitors with ultra-high antiviral potency.     

Protection of marble surfaces by using biodegradable polymers as coating agent

Biodegradable polymers have been replaced over the synthetic polymers in many applications due to their good properties such as reversibility and biodegradability. Therefore they allow new treatment on the surface of the material to be protected and they fulfil the principles generally accepted by the International Conservation Community of Historic Monuments and Buildings.