Search results for: prototype fuel cell electric vehicles

Authors: Ji Jiazheng, Wang Jingrao, Jin Xin, Zhang Hong

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Diabetes mellitus is a metabolic disease characterized by high blood sugar. A long-standing hyperglycemic state can lead to various tissue damage. Diabetic retinopathy is the most common and widely studied ocular complication and has become the leading cause of blindness in my country. At the same time, diabetes has profound clinically relevant effects on the cornea, leading to keratopathy and vision-threatening. The cornea is an avascular tissue and is sensitive to hyperglycemia, Keratopathy caused by diabetes is usually chronic, they are called diabetic keratopathy or diabetic neurotrophic keratopathy, leading to several diabetic corneal complications including delayed epithelial wound healing, recurrent erosions, neuropathy, loss of sensitivity. Corneal stem cell dysfunction in diabetic patients as an important influencing factor of diabetic keratopathy. The consequences of this condition are often underestimated. The limbus is located between the cornea and the sclera tissue. The limbal stroma consists of a series of radial elevations with fibrovascular centers known as palisades of Vogt (POV). Previous studies have shown that palisades of Vogt (POV), as the main site of limbal stem cells, plays an important role in the homeostasis of the corneal epithelium. Therefore, POV plays a vital role in the healing of corneal epithelial surgery and postoperative evaluation. IVCM can observe the condition of the corneal epithelium at the cellular level. It has profound significance and guidance for the evaluation of limbal and limbal stem cells. We have previously observed structural changes in POV in HSK and HZO patients on IVCM. At present, there have been reports involving limbal stem cell dysfunction in diabetic patients, but the specific pathogenesis is still unclear. However, there are no studies on POV morphological changes in patients with DM. Therefore, we performed statistics and compared the correlation between POV morphological changes and corneal epithelial basal cell density, corneal nerves, and length of disease in DM patients and normal humans using IVCM studies. At the same time, fundoscopy was used to observe the correlation between the thickness of RNFL and the thickness of GCC and POV in diabetic patients. And to observe the correlation between SVD, DVD and POV for research.

Keywords: confocal microscopy, fundus, limbal stem cells, diabetes

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Authors: Piotr-Robert Lazik, Harald Garrecht

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Many concrete technologists are looking for a solution to replace Fly Ashes that would be unavailable in a few years as an element that occurs as a major component of many types of concrete. The importance of such component is clear - it saves cement and reduces the amount of CO₂ in the atmosphere that occurs during cement production. Wood Ashes from electrostatic filter can be used as a valuable substitute in concrete. The laboratory investigations showed that the wood ash concrete had a compressive strength comparable to coal fly ash concrete. These results indicate that wood ash can be used to manufacture normal concrete.

Keywords: wood ashes, fly ashes, electric filter, replacement, concrete technology

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Authors: Elvin P. Chizenga, Heidi Abrahamse

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Cancer cell resistance to therapy is the main cause of treatment failures and the poor prognosis of cancer convalescence. The progression of cervical cancer to other parts of the genitourinary system and the reported recurrence rates are overwhelming. Current treatments, including surgery, chemo and radiation have been inefficient in eradicating the tumor cells. These treatments are also associated with poor prognosis and reduced quality of life, including fertility loss. This has inspired the need for the development of new treatment modalities to eradicate cervical cancer successfully. Photodynamic Therapy (PDT) is a modern treatment modality that induces cell death by photochemical interactions of light and a photosensitizer, which in the presence of molecular oxygen, yields a set of chemical reactions that generate Reactive Oxygen Species (ROS) and other free radical species causing cell damage. Enhancing PDT using modified drug delivery can increase the concentration of the photosensitizer in the tumor cells, and this has the potential to maximize its therapeutic efficacy. In cervical cancer, all infected cells constitutively express genes of the E6 and E7 HPV viral oncoproteins, resulting in high concentrations of E6 and E7 in the cytoplasm. This provides an opportunity for active targeting of cervical cancer cells using immune-mediated drug delivery to maximize therapeutic efficacy. The use of nanoparticles in PDT has also proven effective in enhancing therapeutic efficacy. Gold nanoparticles (AuNps) in particular, are explored for their use in biomedicine due to their biocompatibility, low toxicity, and enhancement of drug uptake by tumor cells. In this present study, a biomolecule comprising of AuNPs, anti-E6 monoclonal antibodies, and Aluminium Phthalocyanine photosensitizer was synthesized for use in targeted PDT of cervical cancer. The AuNp-Anti-E6-Sulfonated Aluminium Phthalocyanine mix (AlPcSmix) photosensitizing biomolecule was synthesized by coupling AuNps and anti-E6 monoclonal antibodies to the AlPcSmix via Polyethylene Glycol (PEG) chemical links. The final product was characterized using Transmission Electron Microscope (TEM), Zeta Potential, Uv-Vis Spectrophotometry, Fourier Transform Infrared Spectroscopy (FTIR), and X-ray diffraction (XRD), to confirm its chemical structure and functionality. To observe its therapeutic role in treating cervical cancer, cervical cancer cells, HeLa cells were seeded in 3.4 cm² diameter culture dishes at a concentration of 5x10⁵ cells/ml, in vitro. The cells were treated with varying concentrations of the photosensitizing biomolecule and irradiated using a 673.2 nm wavelength of laser light. Post irradiation cellular responses were performed to observe changes in morphology, viability, proliferation, cytotoxicity, and cell death pathways induced. Dose-Dependent response of the cells to treatment was demonstrated as significant morphologic changes, increased cytotoxicity, and decreased cell viability and proliferation This study presented a synthetic biomolecule for targeted PDT of cervical cancer. The study suggested that PDT using this AuNp- Anti-E6- AlPcSmix photosensitizing biomolecule is a very effective treatment method for the eradication of cervical cancer cells, in vitro. Further studies in vivo need to be conducted to support the use of this biomolecule in treating cervical cancer in clinical settings.

Keywords: anti-E6 monoclonal antibody, cervical cancer, gold nanoparticles, photodynamic therapy

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Authors: Leila Motamed-Jahromi, Mohsen Hatami, Alireza Keshavarz

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This research aims at obtaining the equations of pulse propagation in nonlinear plasmonic waveguides created with As₂S₃ chalcogenide materials. Via utilizing Helmholtz equation and first-order perturbation theory, two components of electric field are determined within frequency domain. Afterwards, the equations are formulated in time domain. The obtained equations include two coupled differential equations that considers nonlinear dispersion.

Keywords: nonlinear optics, plasmonic waveguide, chalcogenide, propagation equation

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Authors: Susan Hall, Gary D. Grant, Catherine McDermott, Devinder Arora

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Introduction /Aim: The kynurenine pathway is thought to play an important role in the pathophysiology of numerous neurodegenerative diseases including depression, Alzheimer’s disease, and Parkinson’s disease. Numerous neuroactive compounds, including the neurotoxic 3-hydroxyanthranilic acid, 3-hydroxykynurenine and quinolinic acid and the neuroprotective kynurenic acid and picolinic acid, are produced through the metabolism of kynurenine and are thought to be the causative agents responsible for neurodegeneration. The toxicity of 3-hydroxykynurenine, 3-hydroxyanthranilic acid and quinolinic acid has been widely evaluated and demonstrated in primary cell cultures but to date only 3-hydroxykynurenine and 3-hydroxyanthranilic acid have been shown to cause toxicity in immortal tumour cells. The aim of this study was to evaluate the toxicity of kynurenine metabolites, both individually and in combination, on SH-SY5Y neuroblastoma cells after 24 and 72 h exposure in order to explore a cost-effective model to study their neurotoxic effects and potential protective agents. Methods: SH-SY5Y neuroblastoma cells were exposed to various concentrations of the neuroactive kynurenine metabolites, both individually and in combination, for 24 and 72 h, and viability was subsequently evaluated using the Resazurin (Alamar blue) proliferation assay. Furthermore, the effects of these compounds, alone and in combination, on specific death pathways including apoptosis, necrosis and free radical production was evaluated using various assays. Results: Consistent with literature, toxicity was shown with short-term 24-hour treatments at 1000 μM concentrations for both 3-hydroxykynurenine and 3-hydroxyanthranilic acid. Combinations of kynurenine metabolites showed modest toxicity towards SH-SY5Y neuroblastoma cells in a concentration-dependent manner. Specific cell death pathways, including apoptosis, necrosis and free radical production were shown to be increased after both 24 and 72 h exposure of SH-SY5Y neuroblastoma cells to 3-hydroxykynurenine and 3-hydroxyanthranilic acid and various combinations of neurotoxic kynurenine metabolites. Conclusion: It is well documented that neurotoxic kynurenine metabolites show toxicity towards primary human neurons in the nanomolar to low micromolar concentration range. Results show that the concentrations required to show significant cell death are in the range of 1000 µM for 3-hydroxykynurenine and 3-hydroxyanthranilic acid and toxicity of quinolinic acid towards SH-SY5Y was unable to be shown. This differs significantly from toxicities observed in primary human neurons. Combinations of the neurotoxic metabolites were shown to have modest toxicity towards these cells with increased toxicity and activation of cell death pathways observed after 72 h exposure. This study suggests that the 24 h model is unsuitable for use in neurotoxicity studies, however, the 72 h model better represents the observations of the studies using primary human neurons and may provide some benefit in providing a cost-effective model to assess possible protective agents against kynurenine metabolite toxicities.

Keywords: kynurenine metabolites, neurotoxicity, quinolinic acid, SH-SY5Y neuroblastoma

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Authors: N. Slepickova Kasalkova, P. Slepicka, L. Bacakova, V. Svorcik

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Tissue engineering includes combination of materials and techniques used for the improvement, repair or replacement of the tissue. Scaffolds, permanent or temporally material, are used as support for the creation of the "new cell structures". For this important component (scaffold), a variety of materials can be used. The advantage of some polymeric materials is their cytocompatibility and possibility of biodegradation. Poly(L-lactic acid) (PLLA) is a biodegradable,  semi-crystalline thermoplastic polymer. PLLA can be fully degraded into H₂O and CO₂. In this experiment, the effect of the surface modification of biodegradable polymer (performed by plasma treatment) on the various cell types was studied. The surface parameters and changes of the physicochemical properties of modified PLLA substrates were studied by different methods. Surface wettability was determined by goniometry, surface morphology and roughness study were performed with atomic force microscopy and chemical composition was determined using photoelectron spectroscopy. The physicochemical properties were studied in relation to cytocompatibility of human osteoblast (MG 63 cells), rat vascular smooth muscle cells (VSMC), and human stem cells (ASC) of the adipose tissue in vitro. A fluorescence microscopy was chosen to study and compare cell-material interaction. Important parameters of the cytocompatibility like adhesion, proliferation, viability, shape, spreading of the cells were evaluated. It was found that the modification leads to the change of the surface wettability depending on the time of modification. Short time of exposition (10-120 s) can reduce the wettability of the aged samples, exposition longer than 150 s causes to increase of contact angle of the aged PLLA. The surface morphology is significantly influenced by duration of modification, too. The plasma treatment involves the formation of the crystallites, whose number increases with increasing time of modification. On the basis of physicochemical properties evaluation, the cells were cultivated on the selected samples. Cell-material interactions are strongly affected by material chemical structure and surface morphology. It was proved that the plasma treatment of PLLA has a positive effect on the adhesion, spreading, homogeneity of distribution and viability of all cultivated cells. This effect was even more apparent for the VSMCs and ASCs which homogeneously covered almost the whole surface of the substrate after 7 days of cultivation. The viability of these cells was high (more than 98% for VSMCs, 89-96% for ASCs). This experiment is one part of the basic research, which aims to easily create scaffolds for tissue engineering with subsequent use of stem cells and their subsequent "reorientation" towards the bone cells or smooth muscle cells.

Keywords: poly(L-lactic acid), plasma treatment, surface characterization, cytocompatibility, human osteoblast, rat vascular smooth muscle cells, human stem cells

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Authors: Sergey V. Sazonov, Anna S. Mogilenskikh, Svetlana S. Deryabina, Denis A. Demidov, Sergey M. Demidov

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The majority of breast cancer (BC) cases are estrogen receptor (ER) positive, and the most common among surrogate molecular biological subtypes is Luminal A. Despite ongoing treatment, drug resistance occurs in a significant proportion of patients, leading to disease recurrence. To determine the sensitivity of a particular tumor to therapy, it is necessary to create an in vitro model, which could then serve as a basis for the selection of personalized therapy for breast cancer. The aim is to evaluate the molecular genetic profile of tumor cells from primary cultures of the Luminal A subtype of breast cancer as a potential model for assessing resistance to therapy. Materials and methods: Primary cell cultures were obtained from a surgical sample in patients with Luminal A subtype of breast cancer when the following inclusion criteria were met: absence of previous therapy and availability of voluntary informed consent. The subtype was determined using the IHC method. Growth was maintained in a serum-free Mammocult™ environment (STEMCELL, Canada). The culture was passed after 7-10 days (p1-p5), and flow cytometry was performed on a Beckman Coulter cytometer (USA) at each passage. Antibodies to estrogen (Alexa Fluor® 647, SP1, Abcam, Canada) to HER2 (24D2, Brilliant Violet 421™, Biolegend, USA) were used for evaluation, and at least 5,000 events were analyzed.). NGS testing was performed on the same cells (Prep&Seq™ U-panel BCEv1, 63 genes). Results: Luminal A subtype includes cases with a Ki-67 threshold of less than 10% of tumor cell nuclei, no HER2 expression (level 0 to 1 points), lack of amplification of the HER2 gene, and high estrogen and/or progesterone levels. The median for RE expression was 66.5% (IQR 7.1) from p1 to p5, and this index didn´t change significantly throughout culture (p<0.001). The presence of Her2 oncoprotein was detected in 5.0% across all passages (IQR 5.2). The data obtained are consistent with the characteristics of the Luminal A subtype. NGS testing detected mutations in genes associated with breast cancer: BARD1, BRCA2, BRIP1, CASP8, CCNE1, CDH1, KEAP1, MSH3, NF1, PALB2, RAD51D, RECQL5, TP53 ZNF217, as well as in genes associated with the Luminal A subtype: PIK3CA, MAP3KI, ESR1. At all passages are detected in the MAP3K1 gene, 7 mutations (3 missenses, 3 synonymous, 1 in-frame) except p2 and p5. A mutation in 1 exon (synonymous) is added at p2 and p5, while no changes are detected in the other genes. Conclusion: Primary cell cultures during the five passages can preserve the expression of RE and the composition of mutations in genes and can be used as an in vitro model. The combination of mutation in ESR1 and MAP3K gene is a potential factor of acquired resistance to therapy in patients with Luminal A breast cancer.

Keywords: breast cancer, Luminal A subtype, primary cell culture, HER2 receptors, estrogen receptors, MAP3K1 gene, ESR1 gene

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Authors: Yufan Mu

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High salinity process water (HSPW) is often applied in copper ore flotation to alleviate freshwater shortage; however, it is detrimental to copper flotation as it strongly enhances copper activation of pyrite. In this study, the depression effect of a strong oxidiser, potassium ferrate (𝐾₂𝐹₄), on the flotation of copper-activated pyrite was tested to realise the selective separation of pyrite from copper minerals (e.g., chalcopyrite) in flotation using HSPW. The flotation results show that when (𝐾₂𝐹₄) was added in the flotation cell during conditioning, (𝐾₂𝐹₄) could selectively depress copper-activated pyrite while improving chalcopyrite flotation. The depression mechanism of (𝐾₂𝐹₄) on pyrite was ascribed to the significant increase in the pulp potential (Eₕ), dissolved oxygen (DO) concentration and the amount of ferric oxyhydroxides as a result of ferrate decomposition. In the flotation cell, the high Eh and DO concentration promoted the oxidation of low valency metal species (𝐶⁺𝐹e²⁺) released from mineral surfaces and forged steel grinding media, and the resultant high valency metal oxyhydroxides 𝐶u(𝑂H)₂⁄Fe(OH)₃ together with the ferric oxyhydroxides from ferrate decomposition preferentially precipitated on pyrite surface due to its more cathodic nature compared with chalcopyrite, which increased pyrite surface hydrophilicity and reduced its floatability. This study reveals that (𝐾₂𝐹₄) is a highly efficient depressant for pyrite when separating copper minerals from pyrite in flotation using HSPW if dosed properly.

Keywords: copper flotation, pyrite depression, copper-activated pyrite, potassium ferrate, high salinity process water

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Authors: Shujun Xie, Shirong Zhang, Shenglin Ma

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Background: Chronic inflammation might lead to many malignancies, and inadequate resolution could play a crucial role in tumor invasion, progression, and metastases. A randomised, double-blind, placebo-controlled trial shows that IL-1β inhibition with canakinumab could reduce incident lung cancer and lung cancer mortality in patients with atherosclerosis. The process and secretion of proinflammatory cytokine IL-1β are controlled by the inflammasome. Here we showed the correlation of the innate immune system and afatinib, a tyrosine kinase inhibitor targeting epidermal growth factor receptor (EGFR) in non-small cell lung cancer. Methods: Murine Bone marrow derived macrophages (BMDMs), peritoneal macrophages (PMs) and THP-1 were used to check the effect of afatinib on the activation of NLRP3 inflammasome. The assembly of NLRP3 inflammasome was check by co-immunoprecipitation of NLRP3 and apoptosis-associated speck-like protein containing CARD (ASC), disuccinimidyl suberate (DSS)-cross link of ASC. Lipopolysaccharide (LPS)-induced sepsis and Alum-induced peritonitis were conducted to confirm that afatinib could inhibit the activation of NLRP3 in vivo. Peripheral blood mononuclear cells (PBMCs) from non-small cell lung cancer (NSCLC) patients before or after taking afatinib were used to check that afatinib inhibits inflammation in NSCLC therapy. Results: Our data showed that afatinib could inhibit the secretion of IL-1β in a dose-dependent manner in macrophage. Moreover, afatinib could inhibit the maturation of IL-1β and caspase-1 without affecting the precursors of IL-1β and caspase-1. Next, we found that afatinib could block the assembly of NLRP3 inflammasome and the ASC speck by blocking the interaction of the sensor protein NLRP3 and the adaptor protein ASC. We also found that afatinib was able to alleviate the LPS-induced sepsis in vivo. Conclusion: Our study found that afatinib could inhibit the activation of NLRP3 inflammasome in macrophage, providing new evidence that afatinib could target the innate immune system to control chronic inflammation. These investigations will provide significant experimental evidence in afatinib as therapeutic drug for non-small cell lung cancer or other tumors and NLRP3-related diseases and will explore new targets for afatinib.

Keywords: inflammasome, afatinib, inflammation, tyrosine kinase inhibitor

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Authors: Fadilah Aleanizy

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Colicins are a family of bacterial toxins that kill Escherichia coli and other closely related species. The mode of action of colicins involves binding to an outer membrane receptor and translocation across the cell envelope, leading to cytotoxicity through specific targets. The mechanism of colicin cytotoxicity includes a non-specific endonuclease activity or depolarization of the cytoplasmic membrane by pore-forming activity. For Group A colicins, translocation requires an interaction between the N-terminal domain of the colicin and a series of membrane- bound and periplasmic proteins known as the Tol system (TolB, TolR, TolA, TolQ, and Pal and the active domain must be translocated through the outer membranes. Protein-protein interactions are intrinsic to virtually every cellular process. The transient protein-protein interactions of the colicin include the interaction with much more complicated assemblies during colicin translocation across the cellular membrane to its target. The potassium release assay detects variation in the K+ content of bacterial cells (K+in). This assays is used to measure the effect of pore-forming colicins such as ColA on an indicator organism by measuring the changes of the K+ concentration in the external medium (K+out ) that are caused by cell killing with a K+ selective electrode. One of the goals of this work is to employ a quantifiable in-vivo method to spot which Tol protein are more implicated in the interaction with colicin A as it is translocated to its target.

Keywords: K+ efflux, Colicin A, Tol-proteins, E. coli

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Authors: Victor Pena Ribeiro, Caroline Arruda, Jennyfer Andrea Aldana Mejia, Jairo Kenupp Bastos

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Leishmaniasis is a serious health problem around the world. The treatment of infected individuals with pentavalent antimonial drugs is the main therapeutic strategy. However, they present high toxicity and persistence side effects. Therefore, the discovery of new and safe natural-derived therapeutic agents against leishmaniasis is important. Propolis is a resin of viscous consistency produced by Apis mellifera bees from parts of plants. The main types of Brazilian propolis are green, red, yellow and brown. Thus, the aim of this work was to investigate the chemical composition and leishmanicidal properties of a brown propolis (BP). For this purpose, the hydroalcoholic crude extract of BP was obtained and was fractionated by liquid-liquid chromatography. The chemical profile of the extract and its fractions were obtained by HPLC-UV-DAD. The fractions were submitted to preparative HPLC chromatography for isolation of the major compounds of each fraction. They were analyzed by NMR for structural determination. The volatile compounds were obtained by hydrodistillation and identified by GC/MS. Promastigote forms of Leishmania amazonensis were cultivated in M199 medium and then 2×106 parasites.mL-1 were incubated in 96-well microtiter plates with the samples. The BP was dissolved in dimethyl sulfoxide (DMSO) and diluted into the medium, to give final concentrations of 1.56, 3.12, 6.25, 12.5, 25 and 50 µg.mL⁻¹. The plates were incubated at 25ºC for 24 h, and the lysis percentage was determined by using a Neubauer chamber. The bioassays were performed in triplicate, using a medium with 0.5% DMSO as a negative control and amphotericin B as a positive control. The leishimnicidal effect against promastigote forms was also evaluated at the same concentrations. Cytotoxicity experiments also were performed in 96-well plates against normal (CHO-k1) and tumor cell lines (AGP01 and HeLa) using XTT colorimetric method. Phenolic compounds, flavonoids, and terpenoids were identified in brown propolis. The major compounds were identified as follows: p-coumaric acid (24.6%) for a methanolic fraction, Artepelin-C (29.2%) for ethyl acetate fraction and the compounds of hexane fraction are in the process of structural elucidation. The major volatile compounds identified were β-caryophyllene (10.9%), germacrene D (9.7%), nerolidol (10.8%) and spathulenol (8.5%). The propolis did not show cytotoxicity against normal cell lines (CHO) with IC₅₀ > 100 μg.mL⁻¹, whereas the IC₅₀ < 10 μg.mL⁻¹ showed a potential against the AGP01 cell line, propolis did not demonstrate cytotoxicity against HeLa cell lines IC₅₀ > 100 μg.mL⁻¹. In the determination of the leishmanicidal activity, the highest (50 μg.mL⁻¹) and lowest (1.56 μg.mL⁻¹) concentrations of the crude extract caused the lysis of 76% and 45% of promastigote forms of L. amazonensis, respectively. To the amastigote form, the highest (50 μg.mL⁻¹) and lowest (1.56 μg.mL⁻¹) concentrations caused the mortality of 89% and 75% of L. amazonensis, respectively. The IC₅₀ was 2.8 μg.mL⁻¹ to amastigote form and 3.9 μg.mL⁻¹ to promastigote form, showing a promising activity against Leishmania amazonensis.

Keywords: amastigote, brown propolis, cytotoxicity, promastigote

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Authors: Godfrey Omulo, Regina Birner, Karlheinz Koller, Thomas Daum

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Conservation agriculture (CA) as a climate-resilient and sustainable practice have been carried out for over three decades in Zambia. However, its continued promotion and adoption has been predominantly on a small-scale basis. Despite the plethora of scholarship pointing to the positive benefits of CA in regard to enhanced yield, profitability, carbon sequestration and minimal environmental degradation, these have not stimulated commensurate agricultural extensification desired for Zambia. The objective of this study was to investigate the potential differences between mechanized conventional and conservation tillage practices on operation time, fuel consumption, labor costs, soil moisture retention, soil temperature and crop yield. An on-farm mechanized conservation agriculture (MCA) experiment arranged in a randomized complete block design with four replications was used. The research was conducted on a 15 ha of sandy loam rainfed land: soybeans on 7ha with plot dimensions of 24 m by 210 m and maize on 8ha with plot dimensions of 24 m by 250 m. The three tillage treatments were: residue burning followed by disc harrowing, ripping tillage and no-till. The crops were rotated in two subsequent seasons. All operations were done using a 60hp 2-wheel tractor, a disc harrow, a two-tine ripper and a two-row planter. Soil measurements and the agro-economic factors were recorded for two farming seasons. The season results showed that the yield of maize and soybeans under no-till and ripping tillage practices were not significantly different from the conventional burning and discing. But, there was a significant difference in soil moisture content between no-till (25.31SFU±2.77) and disced (11.91SFU±0.59) plots at depths from 10-60 cm. Soil temperature in no-till plots (24.59°C±0.91) was significantly lower compared to the disced plots (26.20°C±1.75) at the depths 15 cm and 45 cm. For maize, there was a significant difference in operation time between disc-harrowed (3.68hr/ha±1.27) and no-till (1.85hr/ha±0.04) plots, and a significant difference in cost of labor between disc-harrowed (45.45$/ha±19.56) and no-till (21.76$/ha) plots. There was no significant difference in fuel consumption between ripping and disc-harrowing and direct seeding. For soybeans, there was a significant difference in operation time between no-tillage (1.96hr/ha±0.31) and ripping (3.34hr/ha±0.53) and disc harrowing (3.30hr/ha±0.16). Further, fuel consumption and labor on no-till plots were significantly different from both the ripped and disc-harrowed plots. The high seed emergence percentage on maize disc-harrowed plot (93.75%±5.87) was not significantly different from ripping and no-till plots. Again, the high seed emergence percentage for the soybean ripped plot (93.75%±13.03) had no significant difference with discing and ripping. The results show that it is economically sound and timesaving to practice MCA and get viable yields compared to conventional farming. This research fills the gap on the potential of MCA in the context of Zambia and its profitability in incentivizing policymakers to invest in appropriate and sustainable machinery and implements for extensive agricultural production.

Keywords: climate-smart agriculture, labor cost, mechanized conservation agriculture, soil moisture, Zambia

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Authors: Emma R. Arakelova, Stepan G. Grigoryan, Flora G. Arsenyan, Nelli S. Babayan, Ruzanna M. Grigoryan, Natalia K. Sarkisyan

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Novel nanosize zinc oxide composites of doxorubicin obtained by deposition of 180 nm thick zinc oxide film on the drug surface using DC-magnetron sputtering of a zinc target in the form of gels (PEO+Dox+ZnO and Starch+NaCMC+Dox+ZnO) were studied for drug delivery applications. The cancer specificity was revealed both in in vitro and in vivo models. The cytotoxicity of the test compounds was analyzed against human cancer (HeLa) and normal (MRC5) cell lines using MTT colorimetric cell viability assay. IC50 values were determined and compared to reveal the cancer specificity of the test samples. The mechanistic study of the most active compound was investigated using Flow cytometry analyzing of the DNA content after PI (propidium iodide) staining. Data were analyzed with Tree Star FlowJo software using cell cycle analysis Dean-Jett-Fox module. The in vivo anticancer activity estimation experiments were carried out on mice with inoculated ascitic Ehrlich’s carcinoma at intraperitoneal introduction of doxorubicin and its zinc oxide compositions. It was shown that the nanosize zinc oxide film deposition on the drug surface leads to the selective anticancer activity of composites at the cellular level with the range of selectivity index (SI) from 4 (Starch+NaCMC+Dox+ZnO) to 200 (PEO(gel)+Dox+ZnO) which is higher than that of free Dox (SI = 56). The significant increase in vivo antitumor activity (by a factor of 2-2.5) and decrease of general toxicity of zinc oxide compositions of doxorubicin in the form of the above mentioned gels compared to free doxorubicin were shown on the model of inoculated Ehrlich's ascitic carcinoma. Mechanistic studies of anticancer activity revealed the cytostatic effect based on the high level of DNA biosynthesis inhibition at considerable low concentrations of zinc oxide compositions of doxorubicin. The results of studies in vitro and in vivo behavior of PEO+Dox+ZnO and Starch+NaCMC+Dox+ZnO composites confirm the high potential of the nanosize zinc oxide composites as a vector delivery system for future application in cancer chemotherapy.

Keywords: anticancer activity, cancer specificity, doxorubicin, zinc oxide

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Authors: Sukru Merey, Caglar Sinayuc

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Gas hydrate deposits which are found in deep ocean sediments and in permafrost regions are supposed to be a fossil fuel reserve for the future. The Black Sea is also considered rich in terms of gas hydrates. It abundantly contains gas hydrates as methane (CH₄~80 to 99.9%) source. In this study, by using the literature, seismic and other data of the Black Sea such as salinity, porosity of the sediments, common gas type, temperature distribution and pressure gradient, the optimum gas production method for the Black Sea gas hydrates was selected as mainly depressurization method. Numerical simulations were run to analyze gas production from gas hydrate deposited in turbidites in the Black Sea by depressurization.

Keywords: CH4 hydrate, Black Sea hydrates, gas hydrate experiments, HydrateResSim

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Authors: Sofia N. Gonçalves, Duarte M. S. Albuquerque, José C. F. Pereira

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The energy transition is spurred by structural changes in energy demand, supply, and prices. Microwave technology was first proposed as a faster alternative for cooking food. It was found that food heated instantly when interacting with high-frequency electromagnetic waves. The dielectric properties account for a material’s ability to absorb electromagnetic energy and dissipate this energy in the form of heat. Many energy-intense industries could benefit from electromagnetic heating since many of the raw materials are dielectric at high temperatures. Limestone sedimentary rock is a dielectric material intensively used in the cement industry to produce unslaked lime. A numerical 3D model was implemented in COMSOL Multiphysics to study the limestone continuous processing under microwave heating. The model solves the two-way coupling between the Energy equation and Maxwell’s equations as well as the coupling between heat transfer and chemical interfaces. Complementary, a controller was implemented to optimize the overall heating efficiency and control the numerical model stability. This was done by continuously matching the cavity impedance and predicting the required energy for the system, avoiding energy inefficiencies. This controller was developed in MATLAB and successfully fulfilled all these goals. The limestone load influence on thermal decomposition and overall process efficiency was the main object of this study. The procedure considered the Verification and Validation of the chemical kinetics model separately from the coupled model. The chemical model was found to correctly describe the chosen kinetic equation, and the coupled model successfully solved the equations describing the numerical model. The interaction between flow of material and electric field Poynting vector revealed to influence limestone decomposition, as a result from the low dielectric properties of limestone. The numerical model considered this effect and took advantage from this interaction. The model was demonstrated to be highly unstable when solving non-linear temperature distributions. Limestone has a dielectric loss response that increases with temperature and has low thermal conductivity. For this reason, limestone is prone to produce thermal runaway under electromagnetic heating, as well as numerical model instabilities. Five different scenarios were tested by considering a material fill ratio of 30%, 50%, 65%, 80%, and 100%. Simulating the tube rotation for mixing enhancement was proven to be beneficial and crucial for all loads considered. When uniform temperature distribution is accomplished, the electromagnetic field and material interaction is facilitated. The results pointed out the inefficient development of the electric field within the bed for 30% fill ratio. The thermal efficiency showed the propensity to stabilize around 90%for loads higher than 50%. The process accomplished a maximum microwave efficiency of 75% for the 80% fill ratio, sustaining that the tube has an optimal fill of material. Electric field peak detachment was observed for the case with 100% fill ratio, justifying the lower efficiencies compared to 80%. Microwave technology has been demonstrated to be an important ally for the decarbonization of the cement industry.

Keywords: CFD numerical simulations, efficiency optimization, electromagnetic heating, impedance matching, limestone continuous processing

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Authors: Navid Mirzaei Varzeghani, Mahmoud Saffarzadeh, Ali Naderan, Amirhossein Taheri

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Countries are progressing, and the world's busiest airports see year-on-year increases in travel demand. Passenger acceptability of an airport depends on the airport's appeals, which may include one of these routes between the city and the airport, as well as the facilities to reach them. One of the critical roles of transportation planners is to predict future transportation demand so that an integrated, multi-purpose system can be provided and diverse modes of transportation (rail, air, and land) can be delivered to a destination like an airport. In this study, 356 questionnaires were filled out in person over six days. First, the attraction of business and non-business trips was studied using data and a linear regression model. Lower travel costs, a range of ages more significant than 55, and other factors are essential for business trips. Non-business travelers, on the other hand, have prioritized using personal vehicles to get to the airport and ensuring convenient access to the airport. Business travelers are also less price-sensitive than non-business travelers regarding airport travel. Furthermore, carrying additional luggage (for example, more than one suitcase per person) undoubtedly decreases the attractiveness of public transit. Afterward, based on the manner and purpose of the trip, the locations with the highest trip generation to the airport were identified. The most famous district in Tehran was District 2, with 23 visits, while the most popular mode of transportation was an online taxi, with 12 trips from that location. Then, significant variables in separation and behavior of travel methods to access the airport were investigated for all systems. In this scenario, the most crucial factor is the time it takes to get to the airport, followed by the method's user-friendliness as a component of passenger preference. It has also been demonstrated that enhancing public transportation trip times reduces private transportation's market share, including taxicabs. Based on the responses of personal and semi-public vehicles, the desire of passengers to approach the airport via public transportation systems was explored to enhance present techniques and develop new strategies for providing the most efficient modes of transportation. Using the binary model, it was clear that business travelers and people who had already driven to the airport were the least likely to change.

Keywords: multimodal transportation, demand modeling, travel behavior, statistical models

Procedia PDF Downloads 179

Authors: Adeel Zulifqar, Hong Hu

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Auxetic fabrics are a special kind of textile materials which possess negative Poisson’s ratio. Opposite to most of the conventional fabrics, auxetic fabrics get bigger in the transversal direction when stretched or get smaller when compressed. Auxetic fabrics are superior to conventional fabrics because of their counterintuitive properties, such as enhanced porosity under the extension, excellent formability to a curved surface and high energy absorption ability. Up till today, auxetic fabrics have been produced based on two approaches. The first approach involves using auxetic fibre or yarn and weaving technology to fabricate auxetic fabrics. The other method to fabricate the auxetic fabrics is by using non-auxetic yarns. This method has gained extraordinary curiosity of researcher in recent years. This method is based on realizing auxetic geometries into the fabric structure. In the woven fabric structure auxetic geometries can be realized by creating a differential shrinkage phenomenon into the fabric structural unit cell. This phenomenon can be created by using loose and tight weave combinations within the unit cell of interlacement pattern along with elastic and non-elastic yarns. Upon relaxation, the unit cell of interlacement pattern acquires a non-uniform shrinkage profile due to different shrinkage properties of loose and tight weaves in designed pattern, and the auxetic geometry is realized. The development of uni-stretch auxetic woven fabrics and bi-stretch auxetic woven fabrics by using this method has already been reported. This study reports the development of another kind of bi-stretch auxetic woven fabric. The fabric is first designed by transforming the auxetic geometry into interlacement pattern and then fabricated, using the available conventional weaving technology and non-auxetic elastic and non-elastic yarns. The tensile tests confirmed that the developed bi-stretch auxetic woven fabrics exhibit negative Poisson’s ratio over a wide range of tensile strain. Therefore, it can be concluded that the auxetic geometry can be realized into the woven fabric structure by creating the phenomenon of differential shrinkage and bi-stretch woven fabrics made of non-auxetic yarns having auxetic behavior and stretchability are possible can be obtained. Acknowledgement: This work was supported by the Research Grants Council of Hong Kong Special Administrative Region Government (grant number 15205514).

Keywords: auxetic, differential shrinkage, negative Poisson's ratio, weaving, stretchable

Procedia PDF Downloads 156

Authors: M. Hossain, H. P. Zhu, A. B. Yu

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This paper presents a numerical investigation of regime transition of flow of ellipsoidal particles and a comparison with that of spherical particle assembly. Particle assemblies constituting spherical and ellipsoidal particle of 2.5:1 aspect ratio are examined at separate instances in similar flow conditions in a shear cell model that is numerically developed based on the discrete element method. Correlations among elastically scaled stress, kinetically scaled stress, coordination number and volume fraction are investigated, and show important similarities and differences for the spherical and ellipsoidal particle assemblies. In particular, volume fractions at points of regime transition are identified for both types of particles. It is found that compared with spherical particle assembly, ellipsoidal particle assembly has higher volume fraction for the quasistatic to intermediate regime transition and lower volume fraction for the intermediate to inertial regime transition. Finally, the relationship between coordination number and volume fraction shows strikingly distinct features for the two cases, suggesting that different from spherical particles, the effect of the shear rate on the coordination number is not significant for ellipsoidal particles. This work provides a glimpse of currently running work on one of the most attractive scopes of research in this field and has a wide prospect in understanding rheology of more complex shaped particles in light of the strong basis of simpler spherical particle rheology.

Keywords: DEM, granular rheology, non-spherical particles, regime transition

Procedia PDF Downloads 267

Authors: Josep Domenech Mingot, Francisco Javier Esclapes Jover

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The arrival of the age of information and new technologies allowed humanity to see what the future has in store, but occasionally it also brings the opportunity to look through a window to the past, an opportunity to relive history. This paper introduces a prototype of a digital system that lets us peek into our past making use of augmented reality technologies. A 3D scene will be modeled and animated based on an old image, depicting an event of historical significance. From this scene, a video will be rendered, recreating the events that were taking place at the time. Also, a smartphone app will be created. This app will detect the original image with the smartphone’s camera, overlay the rendered video so that it fully covers it and track the detected image, so that the overlaying video can keep covering the image. The recreation of Alicante’s Central Market bombing during the Spanish Civil War is presented as a case study.

Keywords: augmented reality, digital heritage, history, multimedia, smartphone

Procedia PDF Downloads 225

Authors: T. H. Huang, C. L. Fern, Y. K. Tseng

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The design and reliability of solar photovoltaic modules are crucial to the development of solar energy, and efforts are still being made to extend the life of photovoltaic modules to improve their efficiency because natural aging is time-consuming and does not provide manufacturers and investors with timely information, accelerated aging is currently the best way to estimate the life of photovoltaic modules. Bifacial solar cells not only absorb light from the front side but also absorb light reflected from the ground on the back side, surpassing the performance of single-sided solar cells. Due to the asymmetry of the two sides of the light, in addition to the difference in photovoltaic conversion efficiency, there will also be differences in heat distribution, which will affect the electrical properties and material structure of the bifacial solar cell itself. In this study, there are two types of experimental samples: packaged and unpackaged and then irradiated with UVC light sources and halogen lamps for accelerated aging, as well as a control group without aging. After two weeks of accelerated aging, the bifacial solar cells were visual observation, and infrared thermal images were taken; then, the samples were subjected to IV measurement, and samples were taken for SEM, Raman, and XRD analyses in order to identify the defects that lead to failure and chemical changes, as well as to analyze the reasons for the degradation of their characteristics. From the results of the analysis, it is found that aging will cause carbonization of the polymer material on the surface of bifacial solar cells, and the crystal structure will be affected.

Keywords: bifacial solar cell, accelerated aging, temperature, characterization, electrical measurement

Procedia PDF Downloads 119

Authors: Nandhakumar Elumalai, Purushothaman Ayyakannu, Sachidanandam T. Panchanatham

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Background: Understanding the basic mechanisms and factors underlying the tumor growth and invasion has gained attention in recent times. The processes of angiogenesis and apoptosis are known to play a vital role in various stages of cancer. The vascular endothelial growth factor (VEGF) is well established as one of the key regulators of tumor angiogenesis while MMPs are known for their exclusive ability to degrade ECM. Objective: The present study was designed to evaluate the pro apoptotic and anti angiogenic activity of the herbal formulation Shemamruthaa. The anticancer activity of Shemamruthaa was tested in breast cancer cell line (MCF-7). Results of MTT, trypan blue and flow cytometric analysis of apoptotis suggested that Shemamruthaa can induce cytotoxicity in cancer cells, in a concentration- and time dependent manner and induce apoptosis. With these results, we further evaluated the antiangiogenic and pro-apoptotic activities of Shemamruthaa in DMBA induced mammary carcinoma in Sprague Dawley rats. Flavono tumour was induced in 8-week-old Sprague-Dawley rats by gastric intubation of 25 mg DMBA in 1ml olive oil. After 90 days of induction period, the rats were orally administered with Shemamruthaa (400 mg/kg body wt) for 45 days. Treatment with the drug SM significantly modulated the expression of p53, MMP-2, MMP-3, MMP-9 and VEGF by means of its anti angiogenic and protease inhibiting activity. Conclusion: Based on these results, it might be concluded that the formulation, Shemamruthaa, constituted of dried flowers of Hibiscus rosa-sinensis, fruits of Emblica officinalis, and honey has been found to exhibit pronounced antiproliferative and apoptotic effects. This enhanced anticancer effect of Shemamruthaa might be attributed to the synergistic action of polyphenols such as flavonoids, tannins, alkaloids, glycosides, saponins, steroids, terpenoids, vitamin C, niacin, pyrogallol, hydroxymethylfurfural, trilinolein, and other compounds present in the formulation. Collectively, these results demonstrate that Shemamruthaa holds potential to be developed as a potent chemotherapeutic agent against mammary carcinoma.

Keywords: Shemamruthaa, flavonoids, MCF-7 cell line, mammary cancer

Procedia PDF Downloads 252

Authors: Sara Mota Carmo

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Nowadays, there is an increasing demand for buildings to be energetically autonomous through energy generation systems from renewable sources, according to the concept of a net zero energy building (NZEB). In this sense, the present study aims to study the integration of wind energy through piezoelectricity applied to the building skin. As a methodology, a reduced-scale prototype of a building was developed and tested in a wind tunnel, with the four façades monitored by recording the energy produced by each. The applied wind intensities varied between 2m/s and 8m/s and the four façades were compared with each other regarding the energy produced according to the intensity of wind and position in the wind. The results obtained concluded that it was not a sufficient system to generate sources to cover family residential buildings' energy needs. However, piezoelectricity is expanding and can be a promising path for a wind energy system in architecture as a complement to other renewable energy sources.

Keywords: adaptative building skin, kinetic façade, wind energy in architecture, NZEB

Procedia PDF Downloads 79

Authors: S. D. Abdul, F. B. J. Sawa, D. Z. Andrawus, G. Dan'ilu

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Fresh leaves of twelve accessions of S. indicum were studied to examine their stomatal features, trichomes, epidermal cell shapes and anticlinal cell-wall patterns which may be used for the delimitation of the varieties. The twelve accessions of S. indicum studied have amphistomatic leaves, i.e. having stomata on both surfaces. Four types of stomatal complex types were observed namely, diacytic, anisocytic, tetracytic and anomocytic. Anisocytic type was the most common occurring on both surfaces of all the varieties and occurred 100% in varieties lale-duk, ex-sudan and ex-gombe 6. One-way ANOVA revealed that there was no significant difference between the stomatal densities of ex-gombe 6, ex-sudan, adawa-wula, adawa-ting, ex-gombe 4 and ex-gombe 2 . Accession adawa-ting (improved) has the smallest stomatal size (26.39µm) with highest stomatal density (79.08mm2) while variety adawa-wula possessed the largest stomatal size (74.31µm) with lowest stomatal density (29.60mm2), the exception was found in variety adawa-ting whose stomatal size is larger (64.03µm) but with higher stomatal density (71.54mm2). Wavy, curve or undulate anticlinal wall patterns with irregular and or isodiametric epidermal cell shapes were observed. These accessions were found to exhibit high degree of heterogeneity in their trichome features. Ten types of trichomes were observed: unicellular, glandular peltate, capitate glandular, long unbranched uniseriate, short unbranched uniseriate, scale, multicellular, multiseriate capitate glandular, branched uniseriate and stallate trichomes. The most frequent trichome type is short-unbranched uniseriate, followed by long-unbranched uniseriate (72.73% and 72.5%) respectively. The least frequent was multiseriate capitate glandular (11.5%). The high variation in trichome types and density coupled with the stomatal complex types suggest that these varieties of S. indicum probably have the capacity to conserve water. Furthermore, the leaf micromorphological features varied from one accession to another, hence, are found to be good diagnostic and additional tool in identification as well as nomenclature of the accessions of S. indicum.

Keywords: Sesamum indicum, stomata, trichomes, epidermal cells, taxonomy

Procedia PDF Downloads 282

Authors: M. Jalali Azizpour, H.Mohammadi Majd

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In this paper, the effect of WC-12Co particle Temperature in HVOF thermal spraying process on the coating thickness has been studied. The statistical results show that the spray distance and oxygen-to-fuel ratio are more effective factors on particle characterization and thickness of HVOF thermal spraying coatings. Spray Watch diagnostic system, scanning electron microscopy (SEM), X-ray diffraction and thickness measuring system were used for this purpose.

Keywords: HVOF, temperature, thickness, velocity, WC-12Co

Procedia PDF Downloads 405

Authors: S. Lecheb, A. Chellil, H. Mechakra, S. Attou, H. Kebir

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Although leaf springs are one of the oldest suspension components they are still frequently used, especially in commercial vehicles. Being able to capture the leaf spring characteristics is of significant importance for vehicle handling dynamics studies. The main function of leaf spring is not only to support vertical load but also to isolate road induced vibrations. It is subjected to millions of load cycles leading to fatigue failure. It needs to have excellent fatigue life. The objective of this work is its use of Abaqus software to locate the most stressed areas and predict the areas in which it occurs in fatigue and crack of leaf spring and calculate the stress and frequencies of this model.

Keywords: leaf spring, crack, stress, natural frequencies

Procedia PDF Downloads 468

Authors: S. Mani, M. Kafil, E. Asadi

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Condition Monitoring (CM) of electrical equipment has gained remarkable importance during the recent years; due to huge production losses, substantial imposed costs and increases in vulnerability, risk and uncertainty levels. Power cables feed numerous electrical equipment such as transformers, motors, and electric furnaces; thus their condition assessment is of a very great importance. This paper investigates electrical, structural and environmental failure sources, all of which influence cables' performances and limit their uptimes; and provides a comprehensive framework entailing practical CM guidelines for maintenance of cables in industries. The multilevel CM framework presented in this study covers performance indicative features of power cables; with a focus on both online and offline diagnosis and test scenarios, and covers short-term and long-term threats to the operation and longevity of power cables. The study, after concisely overviewing the concept of CM, thoroughly investigates five major areas of power quality, Insulation Quality features of partial discharges, tan delta and voltage withstand capabilities, together with sheath faults, shield currents and environmental features of temperature and humidity; and elaborates interconnections and mutual impacts between those areas; using mathematical formulation and practical guidelines. Detection, location, and severity identification methods for every threat or fault source are also elaborated. Finally, the comprehensive, practical guidelines presented in the study are presented for the specific case of Electric Arc Furnace (EAF) feeder MV power cables in Mobarakeh Steel Company (MSC), the largest steel company in MENA region, in Iran. Specific technical and industrial characteristics and limitations of a harsh industrial environment like MSC EAF feeder cable tunnels are imposed on the presented framework; making the suggested package more practical and tangible.

Keywords: condition monitoring, diagnostics, insulation, maintenance, partial discharge, power cables, power quality

Procedia PDF Downloads 233

Authors: Emanuela Chiarella, Annamaria Aloisio, Nisticò Clelia, Maria Mesuraca

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ZNF521 is a stem cell-associated transcription co-factor, that plays a crucial role in the homeostatic regulation of the stem cell compartment in the hematopoietic, osteo-adipogenic, and neural system. In normal hematopoiesis, primary human CD34+ hematopoietic stem cells display typically a high expression of ZNF521, while its mRNA levels rapidly decrease when these progenitors progress towards erythroid, granulocytic, or B-lymphoid differentiation. However, most acute myeloid leukemias (AMLs) and leukemia-initiating cells keep high ZNF521 expression. In particular, AMLs are often characterized by chromosomal translocations involving the Mixed Lineage Leukemia (MLL) gene, which MLL gene includes a variety of fusion oncogenes arisen from genes normally required during hematopoietic development; once they are fused, they promote epigenetic and transcription factor dysregulation. The chromosomal translocation t(9;11)(p21-22;q23), fusing the MLL gene with AF9 gene, results in a monocytic immune phenotype with an aggressive course, frequent relapses, and a short survival time. To better understand the dysfunctional transcriptional networks related to genetic aberrations, AML gene expression profile datasets were queried for ZNF521 expression and its correlations with specific gene rearrangements and mutations. The results showed that ZNF521 mRNA levels are associated with specific genetic aberrations: the highest expression levels were observed in AMLs involving t(11q23) MLL rearrangements in two distinct datasets (MILE and den Boer); elevated ZNF521 mRNA expression levels were also revealed in AMLs with t(7;12) or with internal rearrangements of chromosome 16. On the contrary, relatively low ZNF521 expression levels seemed to be associated with the t(8;21) translocation, that in turn is correlated with the AML1-ETO fusion gene or the t(15;17) translocation and in AMLs with FLT3-ITD, NPM1, or CEBPα double mutations. Invitro, we found that the enforced co-expression of ZNF521 in cord blood-derived CD34+ cells induced a significant proliferative advantage, improving MLL-AF9 effects on the induction of proliferation and the expansion of leukemic progenitor cells. Transcriptome profiling of CD34+ cells transduced with either MLL-AF9, ZNF521, or a combination of the two transgenes highlighted specific sets of up- or down-regulated genes that are involved in the leukemic phenotype, including those encoding transcription factors, epigenetic modulators, and cell cycle regulators as well as those engaged in the transport or uptake of nutrients. These data enhance the functional cooperation between ZNF521 and MA9, resulting in the development, maintenance, and clonal expansion of leukemic cells. Finally, silencing of ZNF521 in MLL-AF9-transformed primary CD34+ cells inhibited their proliferation and led to their extinction, as well as ZNF521 silencing in the MLL-AF9+ THP-1 cell line resulted in an impairment of their growth and clonogenicity. Taken together, our data highlight ZNF521 role in the control of self-renewal and in the immature compartment of malignant hematopoiesis, which, by altering the gene expression landscape, contributes to the development and/or maintenance of AML acting in concert with the MLL-AF9 fusion oncogene.

Keywords: AML, human zinc finger protein 521 (hZNF521), mixed lineage leukemia gene (MLL) AF9 (MLLT3 or LTG9), cord blood-derived hematopoietic stem cells (CB-CD34+)

Procedia PDF Downloads 115

Authors: Jeet Chakraborty, Sanjay Dutta

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Antibiotic resistance by bacteria has proved to be a severe threat to mankind in recent times, and this fortifies an urgency to design and develop potent antibacterial small molecules/compounds with nonconventional mechanisms than the conventional ones. DNA carries the genetic signature of any organism, and bacteria maintain their genomic DNA inside the cell in a well-regulated compact form with the help of various nucleoid associated proteins like HU, HNS, etc. These proteins control various fundamental processes like gene expression, replication, etc., inside the cell. Alteration of the native DNA structure of bacteria can lead to severe consequences in cellular processes inside the bacterial cell that ultimately result in the death of the organism. The change in the global DNA structure by small molecules initiates a plethora of cellular responses that have not been very well investigated. Echinomycin and Triostin-A are biologically active Quinoxaline small molecules that typically consist of a quinoxaline chromophore attached with an octadepsipeptide ring. They bind to double-stranded DNA in a sequence-specific way and have high activity against a wide variety of bacteria, mainly against Gram-positive ones. To date, few synthetic quinoxaline scaffolds were synthesized, displaying antibacterial potential against a broad scale of pathogenic bacteria. QNOs (Quinoxaline N-oxides) are known to target DNA and instigate reactive oxygen species (ROS) production in bacteria, thereby exhibiting antibacterial properties. The divergent role of Quinoxaline small molecules in medicinal research qualifies them for the evaluation of their antimicrobial properties as a potential candidate. The previous study from our lab has given new insights on a 6-nitroquinoxaline derivative 1d as an intercalator of DNA, which induces conformational changes in DNA upon binding.7 The binding event observed was dependent on the presence of a crucial benzyl substituent on the quinoxaline moiety. This was associated with a large induced CD (ICD) appearing in a sigmoidal pattern upon the interaction of 1d with dsDNA. The induction of DNA superstructures by 1d at high Drug:DNA ratios was observed that ultimately led to DNA condensation. Eviction of invitro-assembled nucleosome upon treatment with a high dose of 1d was also observed. In this work, monoquinoxaline derivatives of 1d were synthesized by various modifications of the 1d scaffold. The set of synthesized 6-nitroquinoxaline derivatives along with 1d were all subjected to antibacterial evaluation across five different bacteria species. Among the compound set, 3a displayed potent antibacterial activity against Staphylococcus aureus bacteria. 3a was further subjected to various biophysical studies to check whether the DNA structural alteration potential was still intact. The biological response of S. aureus cells upon treatment with 3a was studied using various cell biology processes, which led to the conclusion that 3d can initiate DNA damage in the S. aureus cells. Finally, the potential of 3a in disrupting preformed S.aureus and S.epidermidis biofilms was also studied.

Keywords: DNA structural change, antibacterial, intercalator, DNA superstructures, biofilms

Procedia PDF Downloads 172

Authors: Mogeeb A. El-Sheikh

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The study has developed the previous design of an artificial anthropomorphic humanoid hand and accustomed it as a prosthetic hand. The main specifications of this design are determined. The development of our previous design involves the main artificial hand’s parts and subassemblies, palm, fingers, and thumb. In addition, the study presents an adaptable socket design for a transradial amputee. This hand has 3 fingers and thumb. It is more reliable, cosmetics, modularity, and ease of assembly. Its size and weight are almost as a natural hand. The socket cavity has the capability for different sizes of a transradial amputee. The study implements the developed design by using rapid prototype and specifies its main specifications by using a data glove and finite element method.

Keywords: adaptable socket, prosthetic hand, transradial amputee, data glove

Procedia PDF Downloads 264

Authors: Kiran Shehzadi, Yasmeen Akhtar, Mujahid Ameen, Tabinda Ijaz, Shoukat Siddique

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Nanoparticles, due to their different sizes and morphologies, are employed in various fields such as the medical field, cosmetics, pharmaceutical, textile industry as well as in paints, adhesives, and electronics. Metal nanoparticles exhibit excellent antimicrobial activity, dye degradation and can be used as anti-cancerous drug loading agents. In this study, sZilver nanoparticles (Ag-NPs) were synthesized employing doxycycline (antibiotic) as a reducing and capping agent (biological/green synthesis). Produced Ag-NPS were characterized using UV/VIS spectrophotometry, XRD, SEM, and FTIR. Surface plasmon resonance (SPR) of silver nanoparticles was observed at 411nm with 90nm size with homogenized spherical shape. These particles revealed good inhibition zones for Fungi such as Candida albicans and Candida tropicalis. In this study, toxic properties of Ag-NPs were monitored by allowing them to penetrate in the cell, causing an abrupt increase in oxidative stress, which resulted ultimately in cell death. Histopathological analysis of mice organs was performed by administering definite concentrations of silver nanoparticles orally to mice for 14 days. Toxic properties were determined, and it was revealed that the toxicity of silver nanoparticles mainly depends on the size. Silver nanoparticles of this work presented mild toxicity for different organs (liver, kidney, spleen, heart, and stomach) of mice.

Keywords: metal nanoparticles, green/biological methods, toxicity, Candida albicans, Candida tropicalis

Procedia PDF Downloads 140