Search results for: 7T SRAM cell

Authors: Yakup Sahin, Naim Suleyman Ting, Ismail Aksoy

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In this paper, an improved active snubber cell is proposed on account of soft switching (SS) family of pulse width modulation (PWM) DC-DC converters. The improved snubber cell provides zero-voltage transition (ZVT) turn on and zero-current transition (ZCT) turn off for main switch. The snubber cell decreases EMI noise and operates with SS in a wide range of line and load voltages. Besides, all of the semiconductor devices in the converter operate with SS. There is no additional voltage and current stress on the main devices. Additionally, extra voltage stress does not occur on the auxiliary switch and its current stress is acceptable value. The improved converter has a low cost and simple structure. The theoretical analysis of converter is clarified and the operating states are given in detail. The experimental results of converter are obtained by prototype of 500 W and 100 kHz. It is observed that the experimental results and theoretical analysis of converter are suitable with each other perfectly.

Keywords: active snubber cells, DC-DC converters, zero-voltage transition, zero-current transition

Procedia PDF Downloads 1020

Authors: Virve Pääkkönen, Heidi M. Cuffaro, Leo Tjäderhane

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Objectives: Odontoblasts are the outermost cell layer of dental pulp and form the dentin. Importance of bacterial products, e.g. lipoteichoic acid (LTA), a cell wall component of Gram-positive bacteria and lipopolysaccharide (LPS), a cell wall component of Gram-negative bacteria, have been indicated in the pathogenesis of pulpitis. Gram-positive bacteria are more prevalent in superficial carious lesion while the amount gram-negative is higher in the deep lesions. Objective of this study was to investigate the effect of these bacterial products on inflammatory response of pulp tissue. Interleukins (IL) were of special interest. Various ILs have been observed in the dentin-pulp complex of carious tooth in vivo. Methods: Tissue culture method was used for testing the effect of LTA and LPS on human odontoblasts. Enzymatic isolation technique was used to extract living odontoblasts for cell cultures. DNA microarray and quantitative PCR (qPCR) were used to characterize the changes in the expression profile of the tissue cultured odontoblasts. Laser microdissection was used to cut healthy and affected dentin and odontoblast layer directly under carious lesion for experiments. Cytokine array detecting 80 inflammatory cytokines was used to analyze the protein content of conditioned culture media as well as dentin and odontoblasts from the carious teeth. Results: LPS caused increased gene expression IL-1α, and -8 and decrease of IL-1β, 12 , -15 and -16 after 1h treatment, while after 24h treatment decrease of IL-8, -11 and 23 mRNAs was observed. LTA treatment caused cell death in the tissue cultured odontoblasts but in in the cell culture but not in cell culture. Cytokine array revealed at least 2-fold down-regulation of IL-1β, -10 and -12 in response to LPS treatment. Cytokine array of odontoblasts of carious teeth, as well as LPS-treated tissue-cultured odontoblasts, revealed increased protein amounts of IL-16, epidermal growth factor (EGF), angiogenin and IGFBP-1 as well as decreased amount of fractalkine. In carious dentin, increased amount of IL-1β, EGF and fractalkine was observed, as well as decreased level of GRO-1 and HGF. Conclusion: LPS caused marked changes in the expression of inflammatory cytokines in odontoblasts. Similar changes were observed in the odontoblasts cut directly under the carious lesion. These results help to shed light on the inflammatory processes happening during caries.

Keywords: inflammation, interleukin, lipoteichoic acid, odontoblasts

Procedia PDF Downloads 211

Authors: Abbas Ali Husseini, Ali Mohammad Yazdani, Fatemeh Ghadiri, Alper Şişman

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We developed a microchip device that uses surface acoustic waves for rapid lysis of low level of cell samples. The device incorporates sharp-edge glass microparticles for improved performance. We optimized the lysis conditions for high efficiency and evaluated the device's feasibility for point-of-care applications. The microchip contains a 13-finger pair interdigital transducer with a 30-degree focused angle. It generates high-intensity acoustic beams that converge 6 mm away. The microchip operates at a frequency of 16 MHz, exciting Rayleigh waves with a 250 µm wavelength on the LiNbO3 substrate. Cell lysis occurs when Candida albicans cells and glass particles are placed within the focal area. The high-intensity surface acoustic waves induce centrifugal forces on the cells and glass particles, resulting in cell lysis through lateral forces from the sharp-edge glass particles. We conducted 42 pilot cell lysis experiments to optimize the surface acoustic wave-induced streaming. We varied electrical power, droplet volume, glass particle size, concentration, and lysis time. A regression machine-learning model determined the impact of each parameter on lysis efficiency. Based on these findings, we predicted optimal conditions: electrical signal of 2.5 W, sample volume of 20 µl, glass particle size below 10 µm, concentration of 0.2 µg, and a 5-minute lysis period. Downstream analysis successfully amplified a DNA target fragment directly from the lysate. The study presents an efficient microchip-based cell lysis method employing acoustic streaming and microparticle collisions within microdroplets. Integration of a surface acoustic wave-based lysis chip with an isothermal amplification method enables swift point-of-care applications.

Keywords: cell lysis, surface acoustic wave, micro-glass particle, droplet

Procedia PDF Downloads 79

Authors: Bahareh Asefi, Fereidoun Farzaneh, Ghazaleh Asefi, Chang-Ping Yu

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Increased production of food waste (FW) is a global issue that is receiving more attention due to its environmental and economic impacts. The generation of electricity from food waste, known as energy recovery, is one of the effective solutions in food waste management. Food waste has high energy content which seems ideal to achieve dual benefits in terms of energy recovery and waste stabilization. Microbial fuel cell (MFC) is a promising technology for treating food waste and generate electricity. In this work, we will review energy utilization from different kind of food waste using MFC and factors which affected the process. We have studied the key technology of energy generated from food waste using MFC to enhance the food waste management. The power density and electricity production by each kind of food waste and challenges were identified. This work explored the conversion of FW into energy from different type of food waste, which aim to provide a theoretical analysis for energy utilization of food waste.

Keywords: energy generation, food waste, microbial fuel cell, power density

Procedia PDF Downloads 229

Authors: A. Maria G. Melero, A. M. Senna, J. A. Domingues, M. A. Hausen, E. Aparecida R. Duek, V. R. Botaro

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A hydrogel from cellulose acetate cross linked with ethylenediaminetetraacetic dianhydride (HAC-EDTA) was synthesized by our research group, and submitted to characterization and biological tests. Cytocompatibility analysis was performed by confocal microscopy using human adipocyte derived stem cells (ASCs). The FTIR analysis showed characteristic bands of cellulose acetate and hydroxyl groups and the tensile tests evidence that HAC-EDTA present a Young’s modulus of 643.7 MPa. The confocal analysis revealed that there was cell growth at the surface of HAC-EDTA. After one day of culture the cells presented spherical morphology, which may be caused by stress of the sequestration of Ca²⁺ and Mg²⁺ ions at the cell medium by HAC-EDTA, as demonstrated by ICP-MS. However, after seven days and 14 days of culture, the cells present fibroblastoid morphology, phenotype expected by this cellular type. The results give efforts to indicate this new material as a potential biomaterial for tissue engineering, in the future in vivo approach.

Keywords: cellulose acetate, hydrogel, biomaterial, cellular growth

Procedia PDF Downloads 195

Authors: Mohamed A. Baba, Gazy Rodowan, Brigita Abakevičienė, Sigitas Tamulevičius, Bartlomiej Lemieszek, Sebastian Molin, Tomas Tamulevičius

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Solid oxide fuel cells (SOFC) efficiently convert hydrogen to energy without producing any disturbances or contaminants. The core of the cell is electrolyte. For improving the performance of electrolyte-supported cells, it is desirable to extend the available exchange surface area by micro-structuring of the electrolyte with laser-based micromachining. This study investigated the electrochemical performance of cells micro machined using a femtosecond laser. Commercial ceramic SOFC (Elcogen, AS) with a total thickness of 400 μm was structured by 1030 nm wavelength Yb: KGW fs-laser Pharos (Light Conversion) using 100 kHz repetition frequency and 290 fs pulse length light by scanning with the galvanometer scanner (ScanLab) and focused with a f-Theta telecentric lens (SillOptics). The sample height was positioned using a motorized z-stage. The microstructures were formed using a laser spiral trepanning in Ni/YSZ anode supported membrane at the central part of the ceramic piece of 5.5 mm diameter at active area of the cell. All surface was drilled with 275 µm diameter holes spaced by 275 µm. The machining processes were carried out under ambient conditions. The microstructural effects of the femtosecond laser treatment on the electrolyte surface were investigated prior to the electrochemical characterisation using a scanning electron microscope (SEM) Quanta 200 FEG (FEI). The Novo control Alpha-A was used for electrochemical impedance spectroscopy on a symmetrical cell configuration with an excitation amplitude of 25 mV and a frequency range of 1 MHz to 0.1 Hz. The fuel cell characterization of the cell was examined on open flanges test setup by Fiaxell. Using nickel mesh on the anode side and au mesh on the cathode side, the cell was electrically linked. The cell was placed in a Kittec furnace with a Process IDentifier temperature controller. The wires were connected to a Solartron 1260/1287 frequency analyzer for the impedance and current-voltage characterization. In order to determine the impact of the anode's microstructure on the performance of the commercial cells, the acquired results were compared to cells with unstructured anode. Geometrical studies verified that the depth of the -holes increased linearly according to laser energy and scanning times. On the other hand, it reduced as the scanning speed increased. The electrochemical analysis demonstrates that the open circuit voltage OCV values of the two cells are equal. Further, the modified cell's initial slope reduces to 0.209 from 0.253 of the unmodified cell, revealing that the surface modification considerably decreases energy loss. Plus, the maximum power density for the cell with the microstructure and the reference cell respectively, are 1.45 and 1.16 Wcm⁻².

Keywords: electrochemical performance, electrolyte-supported cells, laser micro-structuring, solid oxide fuel cells

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Authors: Su-Hyun Jung, Young-Su Ryu, Yong-Jun Kim, Hyoung-Kyu Song

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In this paper, a highly efficient coordinated multiple-point (CoMP) scheme for vehicular communication is proposed. The proposed scheme controls the transmit power and applies proper transmission scheme for the various situations. The proposed CoMP scheme provides comparable performance to the conventional dynamic cell selection (DCS) scheme. Moreover, this scheme provides improved power efficiency compared with the conventional joint transmission (JT) scheme. Simulation results show that the proposed scheme can achieve more enhanced performance with the high power efficiency and improve the cell capacity.

Keywords: CoMP, LTE-A, V2I, V2V, V2X.

Procedia PDF Downloads 583

Authors: Igor Sukhotnik

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Objectives: Notch signaling is thought to act to drive cell versification in the lining of the small intestine. When Notch signaling is blocked, proliferation ceases, and epithelial cells become secretory. The purpose of the present study was to evaluate the role of Notch signaling pathway in stem cell differentiation in a rat model of intestinal ischemia-reperfusion (IR). Methods: Male Sprague-Dawley rats were randomly divided into four experimental groups: Sham-24 and Sham-48 rats underwent laparotomy and were killed 24 or 48 h later, respectively; IR-24 and IR-48 rats underwent occlusion of SMA and portal vein for 30 min followed by 24 or 48 h of reperfusion, respectively. Notch-related gene and protein expression were determined using Real Time PCR, Western blotting and immunohistochemistry. Wax histology and immunohistochemistry was used to determine cell differentiation toward absorptive (enterocytes) or secretory progenitors (goblet cells, enteroendocrine cells or Paneth cells). Results: IR-48 rats exhibited a significant decrease in Notch-1 protein expression (Western blot) that was coincided with a significant decrease in the number of Notch-1 positive cells (immunohistochemistry) in jejunum and ileum as well as Hes-1 positive cells in jejunum and ileum compared to Sham-48 rats. A significant down-regulation of Notch signaling related genes and proteins in IR animals was accompanied by a significant increase in the number of goblet and Paneth cells and decreased number of absorptive cells compared to control rats. Conclusions: Forty-eight hours following intestinal IR in rats, inhibited Notch signaling pathway was accompanied by intestinal stem cells differentiation toward secretory progenitors.

Keywords: Intestine, notch, ischemia-reperfusion, cell differentiation, secretory

Procedia PDF Downloads 58

Authors: S. H. Borghei, E. Teymourian, M. Mobin, G. M. Komaki, S. Sheikh

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Imperialist competitive algorithm (ICA) is a recent meta-heuristic method that is inspired by the social evolutions for solving NP-Hard problems. The ICA is a population based algorithm which has achieved a great performance in comparison to other meta-heuristics. This study is about developing enhanced ICA approach to solve the cell formation problem (CFP) using sequence data. In addition to the conventional ICA, an enhanced version of ICA, namely EICA, applies local search techniques to add more intensification aptitude and embed the features of exploration and intensification more successfully. Suitable performance measures are used to compare the proposed algorithms with some other powerful solution approaches in the literature. In the same way, for checking the proficiency of algorithms, forty test problems are presented. Five benchmark problems have sequence data, and other ones are based on 0-1 matrices modified to sequence based problems. Computational results elucidate the efficiency of the EICA in solving CFP problems.

Keywords: cell formation problem, group technology, imperialist competitive algorithm, sequence data

Procedia PDF Downloads 455

Authors: Retno Supriyanti, Best Leader Nababan, Yogi Ramadhani, Wahyu Siswandari

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Blood cell morphology is an important parameter in a hematology test. Currently, in developing countries, a lot of hematology is done manually, either by physicians or laboratory staff. According to the limitation of the human eye, examination based on manual method will result in a lower precision and accuracy. In addition, the hematology test by manual will further complicate the diagnosis in some areas that do not have competent medical personnel. This research aims to develop a simple tool in the detection of blood cell morphology-based computer. In this paper, we focus on the detection of the outer contour of leukocytes. The results show that the system that we developed is promising for detecting blood cell morphology automatically. It is expected, by implementing this method, the problem of accuracy, precision and limitations of the medical staff can be solved.

Keywords: morphology operation, developing countries, hematology test, limitation of medical personnel

Procedia PDF Downloads 337

Authors: Sylwia K. Naliwajko, Justyna Moskwa, Patryk Nowakowski, Renata Markiewicz-Zukowska, Krystyna Gromkowska-Kepka, Anna Puscion-Jakubik, Maria H. Borawska

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Amygdalin is found in many fruit seeds, including apricot, peach, quince, apples, and almonds. Amygdalin (also named vitamin B17), as well as its sources, are commonly used as an alternative therapy or prevention of cancer. The potential activity of amygdalin is related to its enzymatic degradation to the hydrogen cyanide. Hydrogen cyanide is a toxic substance that causes liver and nerves damage, fever, coma or even death. Amygdalin is much better tolerated after intravenous than oral administration. The aim of this study was to examine the influence of amygdalin on glioblastoma multiforme cell lines. Three glioblastoma multiforme cell lines – U87MG, T98, LN18 were incubated (48 h) with amygdalin in concentrations 100, 250, 500, 1000 and 2000 µg/mL. The MTT (Thiazolyl Blue Tetrazolium Bromide) test and DNA binding test by [3H]-thymidine incorporation were used to determine the anti-proliferative activity of amygdalin. The secretion of metalloproteinases (MMP2 and MMP-9) from U87MG cells was estimated by gelatin zymography. The statistical analysis was performed using Statistica v. 13.0 software. The data was presented as a % of control. Amygdalin did not show significant inhibition of viability of all the glioblastoma cells in concentrations 100, 250, 500, 1000 µg/mL. In 2000 µg/mL there were significant differences compared to the control, but inhibition of viability was less than 20% (more than 80% of control). The average viability of U87MG cells was 92,0±4%, T98G: 85,8±3% and LN18: 94,7±2% of the control. There was no dose-response viability, and IC50 value was not recognized. DNA binding in U87MG cells was not inhibited (109,0±3 % of control). After treatment with amygdalin, we observed significantly increased secretion of MMP2 and MMP9 in U87MG cells (130,3±14% and 112,0±5% of control, respectively). Our results suggest that amygdalin has no anticancer activity in glioblastoma cell lines.

Keywords: amygdalin, anticancer, cell line, glioblastoma

Procedia PDF Downloads 216

Authors: Alsulami H., Alghamdi N., Alasker A., Almohen N., Shome D.

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Most conventional chemotherapeutic agents which are used for the treatment of cancers not only eradicate cancer cells but also affect normal hematopoietic Stem cells (HSCs) that leads to severe pancytopenia during treatment. Therefore, a need exists for novel approaches to treat cancer without or with minimum effect on normal HSCs. Parthenolide (PTL), a herbal product occurring naturally in the plant Feverfew, is a potential new chemotherapeutic agent for the treatment of many cancers such as acute myeloid leukemia (AML) and chronic lymphocytic leukemia (CLL). In this study we investigated the effect of different PTL concentrations on the viability of normal HSCs and also on the ability of these cells to form colonies after they have been treated with PTL in vitro. Methods: In this study, 24 samples of bone marrow and cord blood were collected with consent, and mononuclear cells were separated using density gradient separation. These cells were then exposed to various concentrations of PTL for 24 hours. Cell viability after culture was determined using 7ADD in a flow cytometry test. Additionally, the impact of PTL on hematopoietic stem cells (HSCs) was evaluated using a colony forming unit assay (CFU). Furthermore, the levels of NFҝB expression were assessed by using a PE-labelled anti-pNFκBP65 antibody. Results: this study showed that there was no statistically significant difference in the percentage of cell death between untreated and PTL treated cells with 5 μM PTL (p = 0.7), 10 μM PTL (p = 0.4) and 25 μM (p = 0.09) respectively. However, at higher doses, PTL caused significant increase in the percentage of cell death. These results were significant when compared to untreated control (p < 0.001). The response of cord blood cells (n=4) on the other hand was slightly different from that for bone marrow cells in that the percentage of cell death was significant at 100 μM PTL. Therefore, cord blood cells seemed more resistant than bone marrow cells. Discussion &Conclusion: At concentrations ≤25 μM PTL has a minimum or no effect on HSCs in vitro. Cord blood HSCs are more resistant to PTL compared to bone marrow HSCs. This could be due to the higher percentage of T-lymphocytes, which are resistant to PTL, in CB samples (85% in CB vs. 56% in BM. Additionally, CB samples contained a higher proportion of CD34+ cells, with 14.5% of brightly CD34+ cells compared to only 1% in normal BM. These bright CD34+ cells in CB were mostly negative for early-stage stem cell maturation antigens, making them young and resilient to oxidative stress and high concentrations of PTL.

Keywords: stem cell, parthenolide, NFKB, CLL

Procedia PDF Downloads 48

Authors: Diego Luján Villarreal

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Visual prostheses are designed to repair some eyesight in patients blinded by photoreceptor diseases, such as retinitis pigmentosa (RP) and age-related macular degeneration (AMD). Electrode-to-cell proximity has drawn attention due to its implications on secure single-localized stimulation. Yet, few techniques are available for understanding the relationship between the number of cells activated and the current injection. We propose an answering technique by solving the governing equation for time-dependent electrical currents using finite element discretization to obtain the volume of stimulation.

Keywords: visual prosthetic devices, volume for stimulation, FEM discretization, 3D simulation

Procedia PDF Downloads 73

Authors: Mohammad Aladwan

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Alzheimer’s disease (AD) is a widespread dementing illness with a complex and poorly understood etiology. An important role in improving our understanding of the AD process is the modeling of disease-associated changes in tau protein phosphorylation, a protein known to mediate events essential to the onset and progression of AD. A main feature of AD is the abnormal phosphorylation of tau protein and the presence of neurofibrillary tangles. In order to evaluate the respective roles of the microtubule-binding region (MTBR) and alternatively spliced exons in the N-terminal projection domains in AD, we have constructed SHSY-5Y cell lines that stably overexpress four different species of tau protein (4R2N, 4R0N, N(E-2), N(E+2)). Since the toxicity and spreading of tau lesions in AD depends on the interactions of tau with other proteins, we have performed a proteomic analysis of exosome-fraction interactomes for cell lysates and media samples that were isolated from SHSY-5Y cell lines. Functional analysis of tau interactomes based on gene ontology (GO) terms was performed using the String 10.5 database program. The highest number of exosomes proteomes and tau associated proteins were found with 4R2N isoform (2771 and 159) in cell lysate and they have a high strength of connectivity (78%) between proteins, while N(E-2) isoform in the media proteomes has the highest number of proteins and tau associated protein (1829 and 205). Moreover, known AD markers were significantly enriched in secreted interactomes relative to lysate interactomes in the SHSY-5Y cells of tau isoforms lacking exons 2 and 3 in the N-terminal. The lack of exon 2 (E-2) from tau protein can be mediated by tau secretion and spreading to different cells. Enriched functions in the secreted E-2 interactome include signaling and developmental pathways that have been linked to a) tau misprocessing and lesion development and b) tau secretion and which, therefore, could play novel roles in AD pathogenesis.

Keywords: Alzheimer's disease, dementia, tau protein, neurodegenration disease

Procedia PDF Downloads 100

Authors: Forough Ataollahi, Sumit Pramanik, Belinda Pingguan-Murphy, Wan Abu Bakar Bin Wan Abas, Noor Azuan Bin Abu Osman

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Endothelium proliferation is an important process in cardiovascular homeostasis and can be regulated by extracellular environment, as cells can actively sense mechanical environment. In this study, we evaluated endothelial cell proliferation on PDMS/alumina (Al2O3) composites and pure PDMS. The substrates were prepared from pure PDMS and its composites with 5% and 10% Al2O3 at curing temperature 50˚C for 4 h and then characterized by mechanical, structural and morphological analyses. Higher stiffness was found in the composites compared to the pure PDMS substrate. Cell proliferation of the cultured bovine aortic endothelial cells on substrate materials were evaluated via Resazurin assay and 1, 1’-Dioctadecyl-1, 3, 3, 3’, 3’-Tetramethylindocarbocyanine Perchlorate-Acetylated LDL (Dil-Ac-LDL) cell staining, respectively. The results revealed that stiffer substrates promote more endothelial cells proliferation to the less stiff substrates. Therefore, this study firmly hypothesizes that the stiffness elevates endothelial cells proliferation.

Keywords: stiffness, proliferation, bovine aortic endothelial cells, extra cellular matrix, vascular

Procedia PDF Downloads 343

Authors: Waleed Alsaidy, Mourad Mbarki

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In this work, it have investigated the effect of electron irradiation on the output characteristics of n+/p GaAs solar cell. The studied solar cell is exposed to an electron beam with kinetic energy of 1 MeV under AM0 illumination. In this work, it have used our own software to calculate the damage caused by these energetic particles. Indeed, these particles produce severe degradation on the performances of the solar cells. The aim of this work is to investigate the effect of electronic irradiation on the J(V) characteristics upon the fluence of particles φ (electron/cm2). Thereafter, we have evaluated the degradation of its performances such as the short circuit current J_sc, the open circuit voltage V_oc the efficiency η with respect to the fluence φ of electrons. it have shown that the variation of these parameters decrease linearly with the logarithm of the fluence φ, and their degradation begins from a threshold value φ_m. To validate our calculation, we have compared our results with other theoretical and experimental results available in the literature and we have found a good agreement between them.

Keywords: solar cells, GaAs, short circuit current, open circuit voltage, fluence, degradation

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Authors: Nahid Eskandari, Marjan Ghagozolo, Ehsan Almasi

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Introduction: Silymarin, as a polyphenolic flavonoid derived from milk thistle (Silybum marianum), is known to have antioxidant, immunomodulatory, antiproliferative, antifibrotic, and antiviral effects. The goal of this study was to determine immunosuppressive effect of Silymarin on proliferation and apoptosis of human T cells in comparison with Rapamycin and FK506. Methods: Peripheral Blood Mononuclear Cells (PBMCs) from healthy individuals were activated with Con A (5µg/ml) and then treated with Silymarin, Rapamycin and FK506 in various concentrations (0.001, 0.01, 0.1, 1, 10,100 and 200M) for 5 days. PBMCs were examined for proliferation using CFSE assay and the concentration that inhibited 50% of the cell proliferation (IC50) was determined for each treatment. For apoptosis assay using flow cytometry, PBMCs were activated with Con A and treated with IC50 dose of Silymarin, Rapamycin and FK506 for 5 days, then cell apoptosis was analysed by FITC-annexin V/PI staining and flow cytometry. The effects of Silymarin, Rapamycin and FK506 on the activation of PARP (poly ADP ribose polymerase) pathway in PBMCs stimulated with Con A and treated with IC50 dose of drugs for 5 days evaluated using the PathScan cleaved PARP sandwich ELISA kit. Results: This study showed that Silymarin had the ability to inhibit T cell proliferation in vitro. Moreover, our results indicated that 100 μM (P < 0.001) and 200 μM (P < 0.001) of Silymarin has more inhibitory effect on T cells proliferation than FK506 and Rapamycin. Our data showed that the effective doses (IC50) of Silymarin, FK506 and Rapamycin were 3×10-5 µM, 10-8 µM and 10-6 µM respectively. Data showed that the inhibitory effect of Silymarin, FK506 and Rapamycin on T cell proliferation was not due to cytotoxicity and none of these drugs at IC50 concentration had not affected the level of cleaved PARP. Conclusion: Silymarin could be a good candidate for immunosuppressive therapy for certain medical conditions with superior efficacy and lesser toxicity in comparison with other immunosuppressive drugs.

Keywords: silymarin, immunosuppressive effect, rapamycin, immunology

Procedia PDF Downloads 270

Authors: Noora Al Muftah, Reda Rawi, Richard Thompson, Halima Bensmail

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Clinical responses to anticancer therapies are often restricted to a subset of patients. In some cases, mutated cancer genes are potent biomarkers of response to targeted agents. There is an urgent need to identify biomarkers that predict which patients with are most likely to respond to treatment. Systematic efforts to correlate tumor mutational data with biologic dependencies may facilitate the translation of somatic mutation catalogs into meaningful biomarkers for patient stratification. To identify genomic features associated with drug sensitivity and uncover new biomarkers of sensitivity and resistance to cancer therapeutics, we have screened and integrated a panel of several hundred cancer cell lines from different databases, mutation, DNA copy number, and gene expression data for hundreds of cell lines with their responses to targeted and cytotoxic therapies with drugs under clinical and preclinical investigation. We found mutated cancer genes were associated with cellular response to most currently available Glioma cancer drugs and some frequently mutated genes were associated with sensitivity to a broad range of therapeutic agents. By linking drug activity to the functional complexity of cancer genomes, systematic pharmacogenomic profiling in cancer cell lines provides a powerful biomarker discovery platform to guide rational cancer therapeutic strategies.

Keywords: cancer, gene network, Lasso, penalized regression, P-values, unbiased estimator

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Authors: Satoshi Nishimura

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Although much information has been garnered from the genomes of humans and mice, it remains difficult to extend that information to explain physiological and pathological phenomena. This is because the processes underlying life are by nature stochastic and fluctuate with time. Thus, we developed novel "in vivo molecular imaging" method based on single and two-photon microscopy. We visualized and analyzed many life phenomena, including common adult diseases. We integrated the knowledge obtained, and established new models that will serve as the basis for new minimally invasive therapeutic approaches.

Keywords: two photon microscope, intravital visualization, thrombus, artery

Procedia PDF Downloads 373

Authors: Rabah Iratni, Husain El Hasasna, Khawlah Athamneh, Halima Al Sameri, Nehla Benhalilou, Asma Al Rashedi

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Background: Cancer therapies have witnessed great advances in the recent past, however, cancer continues to be a leading cause of death, with colorectal cancer being the fourth cause of cancer-related deaths. Colorectal cancer affects both sexes equally with poor survival rate once it metastasizes. Phytochemicals, which are plant derived compounds, have been on a steady rise as anti-cancer drugs due to the accumulation of evidences that support their potential. Here, we investigated the anticancer effect of Rhus coriaria on colon cancer cells. Material and Method: Human colon cancer HT-29 cell line was used. Protein expression and protein phosphorylation were examined using Western blotting. Transcription activity was measure using Quantitative RT-PCR. Human tumoral clonogenic assay was used to assess cell survival. Senescence was assessed by the senescence-associated beta-galactosidase assay. Results: Rhus coriaria extract (RCE) was found to significantly inhibit the viability and colony growth of human HT-29 colon cancer cells. RCE induced senescence and cell cycle arrest at G1 phase. These changes were concomitant with upregulation of p21, p16, downregulation of cyclin D1, p27, c-myc and expression of Senescence-associated-β-Galactosidase activity. Moreover, RCE induced non-canonical beclin-1independent autophagy and subsequent apoptotic cell death through activation of activation caspase 8 and caspase 7. The blocking of autophagy by 3-methyladenine (3-MA) or chloroquine (CQ) reduced RCE-induced cell death. Further, RCE induced DNA damage, reduced mutant p53 protein level and downregulated phospho-AKT and phospho-mTOR, events that preceded autophagy. Mechanistically, we found that RCE inhibited the AKT and mTOR pathway, a regulator of autophagy, by promoting the proteasome-dependent degradation of both AKT and mTOR proteins. Conclusion: Our findings provide strong evidence that Rhus coriaria possesses strong anti-colon cancer activity through induction of senescence and autophagic cell death, making it a promising alternative or adjunct therapeutic candidate against colon cancer.

Keywords: autophagy, proteasome degradation, senescence, mTOR, apoptosis, Beclin-1

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Authors: Mahboubeh Davoudi Pahnekolayi

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Begonia rex cv. DS-EYWA is a rare, unique cultivar of begonia rex with curly colorful leaves. Optimization of an in vitro efficient regeneration protocol by focusing on transverse Thin Cell Layer (tTCL) petiole explants for high-scale production of such a beautiful cultivar was considered as our main purpose in this experiment. Thus, various concentrations of Plant Growth Regulators (PGRs) including 6-Benzylaminopurine (BAP), Thidiazuron (TDY), and –Naphthaleneacetic Acid (NAA), were selected in a Completely Randomized Design (CRD) to establish and optimize the direct organogenesis efficiency of this cultivar. Cultivation of 1 mm tTCL petiole explants in noted treatments showed that 1.5 mgl-1 BAP + 0.5 mgl-1 NAA can induce the highest number of direct regenerated shoots and lower concentration of BAP (0.5 mgl-1) can be suggested for shoot elongation before rooting stage. Elongated shoots were successfully rooted in MS free basal medium and acclimatized in 1:1 peat moss: perlite sterilized pot mixture.

Keywords: begonia rare cultivar, direct organogenesis, explant type, regeneration, thin cell layering (TCL)

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Authors: Aysha Al Sha'aibi

Abstract:

Algal blooms of the dinoflagellate species Noctiluca scintillans became frequent events in Omani waters. The current study aims at elucidating the abundance, size variation and observations on the feeding mechanism performed by this species during the winter bloom. An attempt was made, to relate observed biological parameters of the Noctiluca population to environmental factors. Field studies spanned the period from December 2014 to April 2015. Samples were collected from Bandar Rawdah (Muscat region) by Bongo nets, twice per week, from the surface and the integrated upper mixed layer. The measured environmental variables were: temperature, salinity, dissolved oxygen, chlorophyll a, turbidity, nitrite, phosphate, wind speed and rainfall. During the winter bloom (from December 2014 through February 2015), the abundance exhibited the highest concentration on 17 February (640.24×106 cell.L-1) in oblique samples and 83.9x103 cell.L-1 in surface samples, with a subsequent decline up to the end of April. The average number of food vacuoles inside Noctiluca cells was 1.5 per cell; the percentage of feeding Noctiluca compared to the entire population varied from 0.01% to 0.03%. Both the surface area of the Noctiluca symbionts (Pedinomonas noctilucae) and cell diameter were maximal in December. In oblique samples the highest average cell diameter and the surface area of symbiont algae were 751.7 µm and 179.2x103 µm2 respectively. In surface samples, highest average cell diameter and the surface area of symbionts were 760 µm and 284.05x103 µm2 respectively. No significant correlations were detected between Noctiluca’s biological parameters and environmental variables except for the correlation between cell diameter and chlorophyll a, also between symbiotic algae surface area and chlorophyll a. The high correlation of chlorophyll a was as a reason of endosymbiotic algae Pedinomonas noctilucae and green Noctiluca enhanced chlorophyll during bloom. All correlations among biological parameters were significant; they are perhaps one of major factors that mediating high growth rates, generating millions of cell per liter in a short time range. The results gained from this study will provide a beneficial background for understanding deeply the development of coastal algal blooms of Noctiluca scintillans. Moreover, results could be used in different applications related to marine environment.

Keywords: abundance, feeding activities, Noctiluca scintillans, Oman

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Authors: Sutinon Yuchomsuk, Satchachon Changthom, Pruet Areesawangvong, Monsiri Jinapen

Abstract:

Background: Esophageal squamous cell carcinoma can be presented with many symptoms, such as dysphagia or weight loss. However, in some circumstances, rare presentations can be found, e.g., dyspnea, which is more common in pulmonary malignancy. And dyspnea is also one of the most common presentations of COVID-19 infection. So, in this case, we can learn from many points in patient symptoms and findings leading to the diagnosis of esophageal squamous cell carcinoma. Method: This research is a case-report study including one patient from Mahasarakham Hospital, Thailand. Data were collected during December 2021. Result: A 55-year-old Thai male patient with an unknown past medical history presented with dyspnea and shortness of breath for the duration of three days prior to admission. His symptom also included cough, fever, and sore throat. Laboratory results indicated that the patient had COVID-19 pneumonia. Further investigation showed that he had cardiac tamponade and suspected pulmonary/esophageal cancer. Lung biopsy and pericardiocentesis were done, which were positive for carcinoma from pericardial effusion but negative for malignancy from the lung biopsy. Later esophagogastroduodenoscopy was done with endoscopic tissue biopsy; the result was positive for squamous cell carcinoma of the esophagus. Conclusion: Most commonly, esophageal cancer is presented with dysphagia or weight loss. However, in some rare cases, patients can also be presented with dyspnea due to cardiac tamponade. And in recent years, COVID-19 has become a pandemic all over the world, sometimes masking symptoms of other diseases. Such as in this case, the patient didn’t improve after the pneumonia was resolved, which led to the final diagnosis of metastatic esophageal cancer.

Keywords: esophageal cancer, cardiac tamponade, metastatic squamous cell carcinoma, COVID-19 infection

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Authors: Hye-Young Shin, Chan Kee Park

Abstract:

Background: To compare the thinning patterns of the ganglion cell-inner plexiform layer (GCIPL) and peripapillary retinal nerve fiber layer (pRNFL) as measured using Cirrus high-definition optical coherence tomography (HD-OCT) in patients with visual field (VF) defects that respect the vertical meridian. Methods: Twenty eyes of eleven patients with VF defects that respect the vertical meridian were enrolled retrospectively. The thicknesses of the macular GCIPL and pRNFL were measured using Cirrus HD-OCT. The 5% and 1% thinning area index (TAI) was calculated as the proportion of abnormally thin sectors at the 5% and 1% probability level within the area corresponding to the affected VF. The 5% and 1% TAI were compared between the GCIPL and pRNFL measurements. Results: The color-coded GCIPL deviation map showed a characteristic vertical thinning pattern of the GCIPL, which is also seen in the VF of patients with brain lesions. The 5% and 1% TAI were significantly higher in the GCIPL measurements than in the pRNFL measurements (all P < 0.01). Conclusions: Macular GCIPL analysis clearly visualized a characteristic topographic pattern of retinal ganglion cell (RGC) loss in patients with VF defects that respect the vertical meridian, unlike pRNFL measurements. Macular GCIPL measurements provide more valuable information than pRNFL measurements for detecting the loss of RGCs in patients with retrograde degeneration of the optic nerve fibers.

Keywords: brain lesion, macular ganglion cell, inner plexiform layer, spectral-domain optical coherence tomography

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Authors: Fouzia Perveen, Rumana Qureshi

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The presently studied twelve anticancer drugs are the cytotoxic agents which inhibit the replication of DNA and activity of enzymes involved in DNA replication namely topoisomerase-II, polymerase and helicase and have shown remarkable anticancer activity in clinical trials. In this study, we performed molecular docking studies of twelve antitumor drugs against DNA and DNA enzymes in the presence and absence of ascorbic acid (AA) and developed the quantitative structure-activity relationship (QSAR) model for anticancer activity screening. A number of electronic and steric descriptors were calculated using MOE software package. QSAR was established showing a correlation of binding strength with various physicochemical descriptors. Out of these twelve, eight cytotoxic drugs were tested on Non-Small Cell Lung Cancer cell lines (H-157 and H-1299) in the absence and presence of ascorbic acid and experimental IC50 values were calculated. From the docking studies, binding constants were calculated indicating the strength of drug-DNA and drug-enzyme complex formation and it was correlated to the IC50 values (both experimental and theoretical). These results can offer useful references for directing the molecular design of DNA enzyme inhibitor with improved anticancer activity.

Keywords: ascorbic acid, binding constant, cytotoxic agents, cell culture, DNA, DNA enzymes, molecular docking

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Authors: Sarim Ahmad

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The Single Cell Gel Electrophoresis Assay (SCGE, known as comet assay) is a potential, uncomplicated, sensitive and state-of-the-art technique for quantitating DNA damage at individual cell level and repair from in vivo and in vitro samples of eukaryotic cells and some prokaryotic cells, being popular in its widespread use in various areas including human biomonitoring, genotoxicology, ecological monitoring and as a tool for research into DNA damage or repair in different cell types in response to a range of DNA damaging agents, cancer risk and therapy. The method involves the encapsulation of cells in a low-melting-point agarose suspension, lysis of the cells in neutral or alkaline (pH > 13) conditions, and electrophoresis of the suspended lysed cells, resulting in structures resembling comets as observed by fluorescence microscopy; the intensity of the comet tail relative to the head reflects the number of DNA breaks. The likely basis for this is that loops containing a break lose their supercoiling and become free to extend towards the anode. This is followed by visual analysis with staining of DNA and calculating fluorescence to determine the extent of DNA damage. This can be performed by manual scoring or automatically by imaging software. The assay can, therefore, predict an individual’s tumor sensitivity to radiation and various chemotherapeutic drugs and further assess the oxidative stress within tumors and to detect the extent of DNA damage in various cancerous and precancerous lesions of oral cavity.

Keywords: comet assay, single cell gel electrophoresis, DNA damage, early detection test

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Authors: Hanan Mohamed Abd Elmoneim, Rawan Saleh AlJawi, Razan Saleh AlJawi, Aseel Abdullah AlMasoudi , Zyad Adnan Turkistani, Anas Abdulkarim Alkhoutani , Ohood Musaed AlJuhani , Hanan Attiyah AlZahrani

Abstract:

Background Esophageal cancer is the eighth most common cancer worldwide. More than 90% of esophageal cancers are either squamous cell carcinoma or adenocarcinoma. Squamous dysplasia is a precancerous lesion for squamous cell carcinoma and Barrett's esophagus is the precancerous lesion for adenocarcinoma. Gastro-esophageal reflux disease (GERD) is the initiation factor for Barrett's esophagus. Cyclooxygenase-2 (COX-2) is a key enzyme in arachidonic metabolism. It appears to play an important role in gastrointestinal carcinogenesis. COX-2 activity may be a potential target for the prevention of cancer progression by selective COX-2 inhibitors, which decrease proliferation and increase apoptosis. Objectives To assess COX-2 expression in premalignant and malignant esophageal epitheliums changes and detect its roles in progression of these lesions. Materials and Methods We analyzed the expression of COX-2 immunohistochemically in 40 esophageal biopsies utilizing the streptavidin-biotin-peroxidase complex method on archival formalin fixed-paraffin embedded blocks. Histopathologically, 17 (42.5%) of cases were non-malignant cases which included GERD, Barrett's esophagus and squamous dysplasia. The malignant cases were 23 (57.5%) squamous cell carcinoma, adenocarcinoma and undifferentiated carcinoma. Results In non-malignant cases 7 (41.2%) out of 17 cases had high COX-2 expression. In squamous cell carcinoma 10 (83.3%) out of 12 cases had high COX-2 expression. The expression of COX-2 was high in all 9 (100%) cases of adenocarcinoma. COX-2 expression is significantly increased (P=0.005 and P=0.0001) in squamous cell carcinoma and adenocarcinoma respectively. There was a significant difference in COX-2 immunoreactivity between malignant and non-malignant lesions (P=0.0003). Conclusion COX-2 is responsible for the progression of esophageal diseases from benign to malignant. We recommend that COX-2 immunohistochemistry should be done routinely for premalignant and malignant esophageal lesions as selective COX-2 inhibitors will be helpful in the treatment. Further studies on molecular and genetic basis of COX-2 expression are needed to unmask its role and relation to progression of esophageal lesions.

Keywords: Cox-2, Esophageal adinocarcinoma, Esophageal squamous cell carcinoma, Immunohistochemistry.

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Authors: Maryam Zahedi Fard, Nazia Abdul Majid, Hapipah Mohd Ali, Mahmood Ameen Abdulla

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New quinazoline schiff base 3-(5-bromo-2-hydroxy-3-methoxybenzylideneamino)-2-(5-bromo-2-hydroxy-3-methoxyphenyl)-2,3-dihydroquinazolin-4(1H)-one was investigated for anticancer activity against MCF-7 human breast cancer cell line with involved mechanism of apoptosis. The compound demonstrated a remarkable antiproliferative effect, with an IC50 value of 3.41 ± 0.34, after 72 hours of treatment. Morphological apoptotic features in treated MCF-7 cells were observed by AO/PI staining. Furthermore, treated MCF-7 cells subjected to apoptosis death, as exhibited by perturbation of mitochondrial membrane potential and cytochrome c release as well as increase in ROS generation. We also found activation of caspases 3/7 and -9. Moreover, acute toxicity test demonstrated the nontoxic nature of the compound in mice. Our results showed the selected compound significantly induce apoptosis in MCF-7 cells via intrinsic pathway, which might be considered as a potent candidate for further in vivo and clinical breast cancer studies.

Keywords: antiproliferative effect, MCF-7 human breast cancer cell line, apoptosis, caspases

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Authors: Gema M. Rodado, Jose M. Olavarrieta

Abstract:

Hydrogen fuel cell technologies have experienced a great boost in the last decades, significantly increasing the production of these devices for both stationary and portable (mainly automotive) applications; these are influenced by two main factors: environmental pollution and energy shortage. A fuel cell is an electrochemical device that converts chemical energy directly into electricity by using hydrogen and oxygen gases as reactive components and obtaining water and heat as byproducts of the chemical reaction. Fuel cells, specifically those of Proton Exchange Membrane (PEM) technology, are considered an alternative to internal combustion engines, mainly because of the low emissions they produce (almost zero), high efficiency and low operating temperatures (< 373 K). The introduction and use of fuel cells in the automotive market requires the development of standardized and validated procedures to test and evaluate their performance in different environmental conditions including vibrations and freeze-thaw cycles. These situations of vibration and extremely low/high temperatures can affect the physical integrity or even the excellent operation or performance of the fuel cell stack placed in a vehicle in circulation or in different climatic conditions. The main objective of this work is the development and validation of vibration and freeze-thaw cycling test procedures for fuel cell stacks that can be used in a vehicle in order to consolidate their safety, performance, and durability. In this context, different experimental tests were carried out at the facilities of the National Hydrogen Centre (CNH2). The experimental equipment used was: A vibration platform (shaker) for vibration test analysis on fuel cells in three axes directions with different vibration profiles. A walk-in climatic chamber to test the starting, operating, and stopping behavior of fuel cells under defined extreme conditions. A test station designed and developed by the CNH2 to test and characterize PEM fuel cell stacks up to 10 kWe. A 5 kWe PEM fuel cell stack in off-operation mode was used to carry out two independent experimental procedures. On the one hand, the fuel cell was subjected to a sinusoidal vibration test on the shaker in the three axes directions. It was defined by acceleration and amplitudes in the frequency range of 7 to 200 Hz for a total of three hours in each direction. On the other hand, the climatic chamber was used to simulate freeze-thaw cycles by defining a temperature range between +313 K and -243 K with an average relative humidity of 50% and a recommended ramp up and rump down of 1 K/min. The polarization curve and gas leakage rate were determined before and after the vibration and freeze-thaw tests at the fuel cell stack test station to evaluate the robustness of the stack. The results were very similar, which indicates that the tests did not affect the fuel cell stack structure and performance. The proposed procedures were verified and can be used as an initial point to perform other tests with different fuel cells.

Keywords: climatic chamber, freeze-thaw cycles, PEM fuel cell, shaker, vibration tests

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Authors: M. Sadeghi, H. Pezeshk, R. Tusserkani, A. Sharifi Zarchi, A. Malekpour, M. Foroughmand, S. Goliaei, M. Totonchi, N. Ansari–Pour

Abstract:

The role and relative importance of intrinsic and extrinsic factors in the development of complex diseases such as cancer still remains a controversial issue. Determining the amount of variation explained by these factors needs experimental data and statistical models. These models are nevertheless based on the occurrence and accumulation of random mutational events during stem cell division, thus rendering cancer development a stochastic outcome. We demonstrate that not only individual genome sequencing is uninformative in determining cancer risk, but also assigning a unique genome sequence to any given individual (healthy or affected) is not meaningful. Current whole-genome sequencing approaches are therefore unlikely to realize the promise of personalized medicine. In conclusion, since genome sequence differs from cell to cell and changes over time, it seems that determining the risk factor of complex diseases based on genome sequence is somewhat unrealistic, and therefore, the resulting data are likely to be inherently uninformative.

Keywords: cancer risk, extrinsic factors, genome sequencing, intrinsic factors

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