cellular systems
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Molecules ◽  
2022 ◽  
Vol 27 (2) ◽  
pp. 333
Magdalena Kluska ◽  
Michał Juszczak ◽  
Jerzy Żuchowski ◽  
Anna Stochmal ◽  
Katarzyna Woźniak

Kaempferol is a well-known antioxidant found in many plants and plant-based foods. In plants, kaempferol is present mainly in the form of glycoside derivatives. In this work, we focused on determining the effect of kaempferol and its glycoside derivatives on the expression level of genes related to the reduction of oxidative stress—NFE2L2, NQO1, SOD1, SOD2, and HO-1; the enzymatic activity of superoxide dismutases; and the level of glutathione. We used HL-60 acute promyelocytic leukemia cells, which were incubated with the anticancer drug etoposide and kaempferol or one of its three glycoside derivatives isolated from the aerial parts of Lens culinaris Medik.—kaempferol 3-O-[(6-O-E-caffeoyl)-β-d-glucopyranosyl-(1→2)]-β-d-galactopyranoside-7-O-β-d-glucuropyranoside (P2), kaempferol 3-O-[(6-O-E-p-coumaroyl)-β-d-glucopyranosyl-(1→2)]-β-d-galactopyranoside-7-O-β-d-glucuropyranoside (P5), and kaempferol 3-O-[(6-O-E-feruloyl)-β-d-glucopyranosyl-(1→2)]-β-d-galactopyranoside-7-O-β-d-glucuropyranoside (P7). We showed that none of the tested compounds affected NFE2L2 gene expression. Co-incubation with etoposide (1 µM) and kaempferol (10 and 50 µg/mL) leads to an increase in the expression of the HO-1 (9.49 and 9.33-fold at 10 µg/mL and 50 µg/mL, respectively), SOD1 (1.68-fold at 10 µg/mL), SOD2 (1.72-fold at 10–50 µg/mL), and NQO1 (1.84-fold at 50 µg/mL) genes in comparison to cells treated only with etoposide. The effect of kaempferol derivatives on gene expression differs depending on the derivative. All tested polyphenols increased the SOD activity in cells co-incubated with etoposide. We observed that the co-incubation of HL-60 cells with etoposide and kaempferol or derivative P7 increases the level of total glutathione in these cells. Taken together, our observations suggest that the antioxidant activity of kaempferol is related to the activation of antioxidant genes and proteins. Moreover, we observed that glycoside derivatives can have a different effect on the antioxidant cellular systems than kaempferol.

2022 ◽  
pp. 69-87
Vijay Prakash ◽  
Lalit Garg ◽  
Jack Azzopardi ◽  
Thomas Camilleri

Since the early 1990s, there has been a lot of enthusiasm for using high-speed connectivity to develop local community links through education, employment possibilities, fostering community events, and enhancing overall sociability within a local region. 5G is the 5th iteration of a broadband network operating on cellular systems. 5G is not only for mobile phones, but it is also the foundation for virtual reality (VR); the internet of things (IoT); and autonomous transport, immersive services, and public infrastructure; and connecting many electronic devices to the internet. In this chapter, first, the authors have discussed the evolution of 1G network to 6G networks by focussing on its potential impact on the quality of life. Further, 5G applications in IoT, autonomous transport, immersive services, and public infrastructure have been discussed. Then the chapter discusses popular advantages, limitations in the current technologies, implementations, and future perspective.

2022 ◽  
Shahi Imam Reja ◽  
Yuichiro Hori ◽  
Takuya Kamikawa ◽  
Kohei Yamasaki ◽  
Miyako Nishiura ◽  

The ability to monitor proteolytic pathways that remove unwanted and damaged proteins from cells is essential for understanding the multiple processes used to maintain cellular homeostasis. In this study, we...

Kabiru Yusuf ◽  
Dahiru Sani Shuaibu ◽  
Suleiman Aliyu Babale

In this paper, we investigated the effect of different channel propagation characteristics on the performance of 4G systems from high altitude platforms (HAPs). The use of High-Altitude Platforms for communication purpose in the past focused mostly on the assumption that the platform is quasi stationary. The technical limitation of the assumption was that of ensuring stability in the positioning of the platform in space. The use of antenna steering and other approaches were proposed as a solution to the said problem. In this paper, we proposed a channel model which account for the motion of the platform. This was done by investigating the effect of Doppler shift on the carrier frequency as the signals propagate between the transmitter and receiver while the High-Altitude Platform is in motion. The basic free space model was used and subjected to the frequency variation caused by the continuous random shift due to the motion of the HAPs. The trajectory path greatly affects the system performance. A trajectory of 30km, 100km and 500km radii were simulated. An acute elevation angle was used in the simulation. The proposed model was also compared to two other channel models to illustrate its performance. The results show that the proposed model behave similar to the existing models except at base station ID 35 and 45 where the highest deviation of 20dBm was observed. Other stations that deviated were less than 2dBm.

Cells ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 3584
Konstantinos Adamopoulos ◽  
Dimitis Koutsouris ◽  
Apostolos Zaravinos ◽  
George I. Lambrou

Biological systems are dynamic systems featuring two very common characteristics; Initial conditions and progression over time. Conceptualizing this on tumour models it can lead to important conclusions about disease progression, as well as the disease’s “starting point”. In the present study we tried to answer two questions: (a) which are the evolving properties of proliferating tumour cells that started from different initial conditions and (b) we have attempted to prove that cell proliferation follows chaotic orbits and it can be described by the use of Poincaré maps. As a model we have used the acute lymphoblastic leukemia cell line CCRF-CEM. Measurements of cell population were taken at certain time points every 24 h or 48 h. In addition to the population measurements flow cytometry studies have been conducted in order to examine the apoptotic and necrotic rate of the system and also the DNA content of the cells as they progress through. The cells exhibited a proliferation rate of nonlinear nature with aperiodic oscillatory behavior. In addition to that, the (positive) Lyapunov indices and the Poincaré representations in phase-space that we performed confirmed the presence of chaotic orbits. Several studies have dealt with the complex dynamic behaviour of animal populations, but few with cellular systems. This type of approach could prove useful towards the understanding of leukemia dynamics, with particular interest in the understanding of leukemia onset and progression.

Sensors ◽  
2021 ◽  
Vol 21 (24) ◽  
pp. 8419
Mikel Celaya-Echarri ◽  
Leyre Azpilicueta ◽  
Fidel Alejandro Rodríguez-Corbo ◽  
Peio Lopez-Iturri ◽  
Victoria Ramos ◽  

The densification of multiple wireless communication systems that coexist nowadays, as well as the 5G new generation cellular systems advent towards the millimeter wave (mmWave) frequency range, give rise to complex context-aware scenarios with high-node density heterogeneous networks. In this work, a radiofrequency electromagnetic field (RF-EMF) exposure assessment from an empirical and modeling approach for a large, complex indoor setting with high node density and traffic is presented. For that purpose, an intensive and comprehensive in-depth RF-EMF E-field characterization study is provided in a public library study case, considering dense personal mobile communications (5G FR2 @28 GHz) and wireless 802.11ay (@60 GHz) data access services on the mmWave frequency range. By means of an enhanced in-house deterministic 3D ray launching (3D-RL) simulation tool for RF-EMF exposure assessment, different complex heterogenous scenarios of high complexity are assessed in realistic operation conditions, considering different user distributions and densities. The use of directive antennas and MIMO beamforming techniques, as well as all the corresponding features in terms of radio wave propagation, such as the body shielding effect, dispersive material properties of obstacles, the impact of the distribution of scatterers and the associated electromagnetic propagation phenomena, are considered for simulation. Discussion regarding the contribution and impact of the coexistence of multiple heterogeneous networks and services is presented, verifying compliance with the current established international regulation limits with exposure levels far below the aforementioned limits. Finally, the proposed simulation technique is validated with a complete empirical campaign of measurements, showing good agreement. In consequence, the obtained datasets and simulation estimations, along with the proposed RF-EMF simulation tool, could be a reference approach for the design, deployment and exposure assessment of the current and future wireless communication technologies on the mmWave spectrum, where massive high-node density heterogeneous networks are expected.

2021 ◽  
Ray Chang ◽  
Manu Prakash

Cellular systems are known to exhibit some of the fastest movements in the biological world - but little is known as to how single cells can dissipate this energy rapidly and adapt to such large accelerations without sub-cellular damage. To study intracellular adaptations under extreme forces - we investigate Spirostomum ambiguum - a giant cell (1-4mm in length) well known to exhibit ultrafast contractions (50% of body length) within 5 msec with a peak acceleration of 15g. Utilizing transmitted electron microscopy (TEM) and confocal imaging, we discover a novel association of rough endoplasmic reticulum (RER) and vacuoles throughout the cell - forming a contiguous fenestrated cubic membrane architecture that topologically entangles these two organelles. A nearly uniform inter-organelle spacing of 60nm is observed between RER and vacuoles, closely packing the entire cell. Using an overdamped molecular dynamics simulation, we demonstrate how this unique entangled metamaterial responds to external loads by rapidly dissipating energy and helps preserve spatial relationships between organelles. Because this dynamics arises primarily from entanglement of two networks incurring jamming transition at a subcritical volume fraction - we term this phenomena "topological damping". Our findings suggest a new mechanical role of RER-vacuolar meshwork as a metamaterial capable of dissipating energy in an ultra-fast contraction event.

2021 ◽  
Stefan Kotschi ◽  
Anna Jung ◽  
Nienke Willemsen ◽  
Anahita Ofoghi ◽  
Bettina Proneth ◽  

Ferroptosis continues to emerge as a novel modality of cell death with important therapeutic implications for a variety of diseases, most notably cancer and degenerative diseases. While susceptibility, initiation, and execution of ferroptosis have been linked to reprogramming of cellular lipid metabolism, imbalances in iron-redox homeostasis, and aberrant mitochondrial respiration, the detailed mechanisms of ferroptosis are still insufficiently well understood. Here we show that diminished proteasome function is a new mechanistic feature of ferroptosis. The transcription factor nuclear factor erythroid-2, like-1 (NFE2L1) protects from ferroptosis by sustaining proteasomal activity. In cellular systems, loss of NFE2L1 reduced cellular viability after the induction of both chemically and genetically induced ferroptosis, which was linked to the regulation of proteasomal activity under these conditions. Importantly, this was reproduced in a Sedaghatian-type Spondylometaphyseal Dysplasia (SSMD) patient-derived cell line carrying mutated glutathione peroxidase-4 (GPX4), a critical regulator of ferroptosis. Also, reduced proteasomal activity was associated with ferroptosis in Gpx4-deficient mice. In a mouse model for genetic Nfe2l1 deficiency, we observed brown adipose tissue (BAT) involution, hyperubiquitination of ferroptosis regulators, including the GPX4 pathway, and other hallmarks of ferroptosis. Our data highlight the relevance of the NFE2L1-proteasome pathway in ferroptosis. Manipulation of NFE2L1 activity might enhance ferroptosis-inducing cancer therapies as well as protect from aberrant ferroptosis in neurodegeneration, general metabolism, and beyond.

Sensors ◽  
2021 ◽  
Vol 21 (24) ◽  
pp. 8296
Cezary Ziółkowski ◽  
Jan M. Kelner ◽  
Jarosław Krygier ◽  
Aniruddha Chandra ◽  
Aleš Prokeš

The basic technology that will determine the expansion of the technical capabilities of fifth generation cellular systems is a massive multiple-input-multiple-output. Therefore, assessing the influence of the antenna beam orientations on the radio channel capacity is very significant. In this case, the effects of mismatching the antenna beam directions are crucial. In this paper, the methodology for evaluating changes in the received signal power level due to beam misalignment for the transmitting and receiving antenna systems is presented. The quantitative assessment of this issue is presented based on simulation studies carried out for an exemplary propagation scenario. For non-line-of-sight (NLOS) conditions, it is shown that the optimal selection of the transmitting and receiving beam directions may ensure an increase in the level of the received signal by several decibels in relation to the coaxial position of the beams. The developed methodology makes it possible to analyze changes in the radio channel capacity versus the signal-to-noise ratio and distance between the transmitter and receiver at optimal and coaxial orientations of antenna beams for various propagation scenarios, considering NLOS conditions. In the paper, the influence of the directional antenna use and their direction choices on the channel capacity versus SNR and the distance between the transmitter and receiver is shown.

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