Search results for: resistant microbial strains

Authors: Douhi Reda Bouabdellah, Khalafi Hamid, Belamri Samir

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The desire to improve the safety of nuclear reactor containment has revealed the need for data on the thermo mechanical behavior of concrete in case of accident during which the concrete is exposed to high temperatures. The aim of the present work is to study the influence of high temperature on the behavior of ordinary concrete specimens loaded by an effort of compression. A thermal model is developed by discretization volume elements (CASTEM). The results of different simulations, combined with other findings help to bring a physical phenomenon explanation Thermo mechanical concrete structures, which allowed to obtain the variation of the stresses anywhere in point or node and each subsequent temperature different directions X, Y and Z.

Keywords: concrete, thermic-gradient, fire resistant, simulation by CASTEM, mechanical strength

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Authors: Harminder Singh

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Cold spray is a novel and emerging technology for the fabrication of coating. In this study, coating is successfully developed by this process on superalloy surface. The selected coating composition is already proved as corrosion resistant. The microstructure of the newly developed coating is examined by various characterization techniques, for testing its suitability for high temperature corrosive conditions of waste incinerator. The energy producing waste incinerators are still running at low efficiency, mainly due to their chlorine based highly corrosive conditions. The characterization results show that the developed cold sprayed coating structure is suitable for its further testing in highly aggressive conditions.

Keywords: coating, cold spray, corrosion, microstructure

Procedia PDF Downloads 385

Authors: Ismail Haddad, Djamel Herbadji, Aissa Belmeguenai, Selma Boumerdassi

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in this paper, we provide a novel approach for image encryption that employs the Fibonacci matrix and an enhanced fractional order chaotic map. The enhanced map overcomes the drawbacks of the classical map, especially the limited chaotic range and non-uniform distribution of chaotic sequences, resulting in a larger encryption key space. As a result, this strategy improves the encryption system's security. Our experimental results demonstrate that our proposed algorithm effectively encrypts grayscale images with exceptional efficiency. Furthermore, our technique is resistant to a wide range of potential attacks, including statistical and entropy attacks.

Keywords: image encryption, logistic map, fibonacci matrix, grayscale images

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Authors: Ibrahim Isah Lakan, Nasiru Ibrahim

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These Phytochemical screening, Antimicrobial activities and mineral Determination of aqueous extract of Stachtarpheta indica were assessed. The result reveals the presence of flavonoids, tannins, saponins, alkaloids, glycosides and anthraquinones. The disc diffusion of aqueous extract showed Escherichia coli, 13 and antibiotic, 19 mm; Bacillus subtilis, 10 and anti –biotic, 17 mm; Klebsiller pnemuoniae , 14 and antibiotic, 24mm and Pseudmonas aeruginosa, 24 and antibiotic, 36 mm which are all comparable with the standard antibiotic cyprotomycin. The mineral content determination by flame photometer revealed that 1.25 (Na+), 0.85 (K +), 1.75 (Ca 2+) % which is a clear indication of the safety of the extract for the hypertensive patients and could be used to lower blood pressure.

Keywords: microbials, mineral, phytochemicals, stachtarpheta indica extracts

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Authors: Veerle Van Hoeck, Ingrid Somers, Dany Morisset

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Anti-nutritional factors such as non-starch polysaccharides (NSP) are present in viscous cereals used to feed poultry. Therefore, exogenous carbohydrases are commonly added to monogastric feed to degrade these NSP. Our hypothesis is that xylanase not only improves laying hen performance and digestibility but also induces a significant shift in microbial composition within the intestinal tract and, thereby, can cause a prebiotic effect. In this context, a better understanding of whether and how the chicken gut flora can be modulated by xylanase is needed. To do so, in the herein laying hen study, the effects of dietary supplementation of xylanase on performance, digestibility, and cecal microbiome were evaluated. A total of 96 HiSex laying hens was used in this experiment (3 diets and 16 replicates of 2 hens). Xylanase was added to the diets at concentrations of 0, 45,000 (15 g/t XygestTM HT) and 90,000 U/kg (30 g/t Xygest HT). The diets were based on wheat (~55 %), soybean, and sunflower meal. The lowest dosage, 45,000 U/kg, significantly increased average egg weight and improved feed efficiency compared to the control treatment (p < 0.05). Egg quality parameters were significantly improved in the experiment in response to the xylanase addition. For example, during the last 28 days of the trial, the 45,000 U/kg and the 90,000 U/kg treatments exhibited an increase in Haugh units and albumin heights (p < 0.05). Compared with the control, organic matter digestibility and N retention were drastically improved in the 45,000 U/kg treatment group, which implies better nutrient digestibility at this lowest recommended dosage compared to the control (p < 0.05). Furthermore, gross energy and crude fat digestibility were improved significantly for birds fed 90,000 U/kg group compared to the control. Importantly, 16S rRNA gene analysis revealed that xylanase at 45,000 U/kg dosages can exert a prebiotic effect. This conclusion was drawn based on studying the sequence variation in the 16S rRNA gene in order to characterize diverse microbial communities of the cecal content. A significant increase in beneficial bacteria (Lactobacilli spp and Enterococcus casseliflavus) was documented when adding 45,000 U/kg xylanase to the diet of laying hens. In conclusion, dietary supplementation of xylanase, even at the lowest dose of (45,000 U/kg), significantly improved laying hen performance and digestibility. Furthermore, it is generally accepted that a proper bacterial balance between the number of beneficial bacteria and pathogenic bacteria in the intestine is vital for the host. It seems that the xylanase enzyme is able to modulate the laying hen microbiome beneficially and thus exerts a prebiotic effect. This microbiome plasticity in response to the xylanase provides an attractive target for stimulating intestinal health.

Keywords: laying hen, prebiotic, XygestTM HT, xylanase

Procedia PDF Downloads 117

Authors: Rachel Danielson, Brendan Bohannan, S.M. Tsai, Kyle Meyer, Jorge L.M. Rodrigues

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The Amazon Rainforest is a global diversity hotspot and crucial carbon sink, but approximately 20% of its total extent has been deforested- primarily for the establishment of cattle pasture. Understanding the impact of this large-scale disturbance on soil microbial community composition and activity is crucial in understanding potentially consequential shifts in nutrient or greenhouse gas cycling, as well as adding to the body of knowledge concerning how these complex communities respond to human disturbance. In this study, surface soils (0-10cm) were collected from three forests and three 45-year-old pastures in Rondonia, Brazil (the Amazon state with the greatest rate of forest destruction) in order to determine the impact of forest conversion on microbial communities involved in nitrogen fixation. Soil chemical and physical parameters were paired with measurements of microbial activity and genetic profiles to determine how community composition and process rates relate to environmental conditions. Measuring both the natural abundance of 15N in total soil N, as well as incorporation of enriched 15N2 under incubation has revealed that conversion of primary forest to cattle pasture results in a significant increase in the rate of nitrogen fixation by free-living diazotrophs. Quantification of nifH gene copy numbers (an essential subunit encoding the nitrogenase enzyme) correspondingly reveals a significant increase of genes in pasture compared to forest soils. Additionally, genetic sequencing of both nifH genes and transcripts shows a significant increase in the diversity of the present and metabolically active diazotrophs within the soil community. Levels of both organic and inorganic nitrogen tend to be lower in pastures compared to forests, with ammonium rather than nitrate as the dominant inorganic form. However, no significant or consistent differences in total, extractable, permanganate-oxidizable, or loss-on-ignition carbon are present between the two land-use types. Forest conversion is associated with a 0.5- 1.0 unit pH increase, but concentrations of many biologically relevant nutrients such as phosphorus do not increase consistently. Increases in free-living diazotrophic community abundance and activity appear to be related to shifts in carbon to nitrogen pool ratios. Furthermore, there may be an important impact of transient, low molecular weight plant-root-derived organic carbon on free-living diazotroph communities not captured in this study. Preliminary analysis of nitrogenase gene variant composition using NovoSeq metagenomic sequencing indicates that conversion of forest to pasture may significantly enrich vanadium-based nitrogenases. This indication is complemented by a significant decrease in available soil molybdenum. Very little is known about the ecology of diazotrophs utilizing vanadium-based nitrogenases, so further analysis may reveal important environmental conditions favoring their abundance and diversity in soil systems. Taken together, the results of this study indicate a significant change in nitrogen cycling and diazotroph community composition with the conversion of the Amazon Rainforest. This may have important implications for the sustainability of cattle pastures once established since nitrogen is a crucial nutrient for forage grass productivity.

Keywords: free-living diazotrophs, land use change, metagenomic sequencing, nitrogen fixation

Procedia PDF Downloads 185

Authors: Xu Chen, Zhao Caiqi

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In addition to the advantages of light weight, resistant corrosion and ease of processing, aluminum is also applied to the long-span spatial structures. However, the elastic modulus of aluminum is lower than that of the steel. This paper combines the high performance aluminum honeycomb panel with the aluminum latticed shell, forming a new panel-and-rod composite shell structure. Through comparative analysis between the static and dynamic performance, the conclusion that the structure of composite shell is noticeably superior to the structure combined before.

Keywords: combination of aluminum honeycomb panel, rod latticed shell, dynamic performence, response spectrum analysis, seismic properties

Procedia PDF Downloads 462

Authors: Agnese Natali, Francesco Morelli, Walter Salvatore

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Automated Rack Supported Warehouses (ARSWs) are structures currently designed as steel racks. Even if there are common characteristics, there are differences that don’t allow to adopt the same design approach. Aiming to highlight the factors influencing the design and the behavior of ARSWs, a set of 5 structures designed by 5 European companies specialized in this field is used to perform both a critical analysis of the design approaches and the assessment of the seismic performance, which is used to point out the criticalities and the necessity of new design philosophy.

Keywords: steel racks, automated rack supported warehouse, thin walled cold-formed elements, seismic assessment

Procedia PDF Downloads 154

Authors: Fulwah Alqahtani, Jafar Mahdavi, Lee Weldon, Nick Holliday, Dlawer Ala'Aldeen

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There are two isoforms of laminin receptor; monomeric 37 kDa laminin receptor precursor (37 LRP) and mature 67 kDa laminin receptor (67 LR). The relationship between the 67 LR and its precursor 37 LRP is not completely understood, but previous observations have suggested that 37 LRP can undergo homo- and/or hetero- dimerization with Galectin-3 (Gal-3) to form mature 67 LR. Gal-3 is the only member of the chimera-type group of galectins, and has one C-terminal carbohydrate recognition domain (CRD) that is responsible for binding the ß-galactoside moieties of mono- or oligosaccharides on several host and microbial molecules. The aim of this work was to investigate homo- and hetero-dimerization among the 37 LRP and Gal-3 to form mature 67 LR in mammalian cells using bimolecular fluorescence complementation (BiFC).

Keywords: 37 LRP, 67 LR, Gal-3, BiFC

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Authors: Tanima Chatterjee, Maitree Bhattacharyya

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The global challenge of type 2 diabetes mellitus is a major health concern in this millennium, and researchers are continuously exploring new targets to develop a novel therapeutic strategy. Type 2 diabetes mellitus (T2DM) is often coupled with dyslipidemia increasing the risks for cardiovascular (CVD) complications. Enhanced oxidative and nitrosative stresses appear to be the major risk factors underlying insulin resistance, dyslipidemia, β-cell dysfunction, and T2DM pathogenesis. Autophagy emerges to be a promising defense mechanism against stress-mediated cell damage regulating tissue homeostasis, cellular quality control, and energy production, promoting cell survival. In this study, we have attempted to explore the pivotal role of autophagy in T2DM subjects with or without dyslipidemia in peripheral blood mononuclear cells and insulin-resistant HepG2 cells utilizing flow cytometric platform, confocal microscopy, and molecular biology techniques like western blotting, immunofluorescence, and real-time polymerase chain reaction. In the case of T2DM with dyslipidemia higher population of autophagy, positive cells were detected compared to patients with the only T2DM, which might have resulted due to higher stress. Autophagy was observed to be triggered both by oxidative and nitrosative stress revealing a novel finding of our research. LC3 puncta was observed in peripheral blood mononuclear cells and periphery of HepG2 cells in the case of the diabetic and diabetic-dyslipidemic conditions. Increased expression of ATG5, LC3B, and Beclin supports the autophagic pathway in both PBMC and insulin-resistant Hep G2 cells. Upon blocking autophagy by 3-methyl adenine (3MA), the apoptotic cell population increased significantly, as observed by caspase‐3 cleavage and reduced expression of Bcl2. Autophagy has also been evidenced to control oxidative stress-mediated up-regulation of inflammatory markers like IL-6 and TNF-α. To conclude, this study elucidates autophagy to play a protective role in the case of diabetes mellitus with dyslipidemia. In the present scenario, this study demands to have a significant impact on developing a new therapeutic strategy for diabetic dyslipidemic subjects by enhancing autophagic activity.

Keywords: autophagy, apoptosis, dyslipidemia, reactive oxygen species, reactive nitrogen species, Type 2 diabetes

Procedia PDF Downloads 125

Authors: Z. C. Dlamini, R. L. S. Langa, A. I. Okoh, O. A. Aiyegoro

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The indiscriminate usage of antibiotics in swine production have consequential outcomes; such as development of bacterial resistance to prophylactic antibiotics and possibility of antibiotic residues in animal products. The use of probiotics appears to be the most effective procedure with positive metabolic nutritional implications. The aim of this study was to investigate the efficacy of probiotic bacteria (Lactobacillus reuteri ZJ625, Lactobacillus reuteri VB4, Lactobacillus salivarius ZJ614 and Streptococcus salivarius NBRC13956) administered as direct-fed microorganisms in weaned piglets. 45 weaned piglets blocked by weight were dived into 5 treatments groups: diet with antibiotic, diet with no-antibiotic and no probiotic, and diet with probiotic and diet with combination of probiotics. Piglets performance was monitored during the trials. Faecal and Ileum samples were collected for microbial count analysis. Blood samples were collected from pigs at the end of the trial, for analysis of haematological, biochemical and IgG stimulation. The data was analysed by Split-Plot ANOVA using SAS statistically software (SAS 9.3) (2003). The difference was observed between treatments for daily weight and feed conversion ratio. No difference was observed in analysis of faecal samples in regards with bacterial counts, difference was observed in ileums samples with enteric bacteria colony forming unit being lower in P2 treatment group as compared with lactic acid and total bacteria. With exception of globulin and albumin, biochemistry blood parameters were not affected, likewise for haematology, only basophils and segmented neutrophils were differed by having higher concentration in NC treatment group as compared with other treatment groups. Moreover, in IgG stimulation analysis, difference was also observed, with P2 treatment group having high concentration of IgG in P2 treatment group as compared to other groups. The results of this study suggest that probiotics have a beneficial effect on growth performances, blood parameters and IgG stimulation of pigs, most effective when they are administered in synergy form. This means that it is most likely that these probiotics will offer a significant benefit in pig farming by reducing risk of morbidity and mortality and produce quality meat that is more affordable to poorer communities, and thereby enhance South African pig industry’s economy. In addition, these results indicate that there is still more research need to be done on probiotics in regards with, i.e. dosage, shelf life and mechanism of action.

Keywords: antibiotics, biochemistry, haematology, IgG-stimulation, microbial count, probiotics

Procedia PDF Downloads 287

Authors: Mohsen Abdelrazek Khorshid Ali Selim

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Disadvantages and errors of current concrete reinforcement methodsL: Current concrete reinforcement methods are adopted in most parts of the world in their various doctrines and names. They adopt the so-called concrete slab system, where these slabs are semi-independent and isolated from each other and from the surrounding environment of concrete columns or beams, so that the reinforcing steel does not cross from one slab to another or from one slab to adjacent columns. It or the beams surrounding it and vice versa are only a few centimeters and no more. The same applies exactly to the concrete columns that support the building, where the reinforcing steel does not extend from the slabs or beams to the inside of the columns or vice versa except for a few centimeters and no more, just as the reinforcing steel does not extend from inside the column at the top. The ceiling is only a few centimetres, and the same thing is literally repeated in the concrete beams that connect the columns and separate the slabs, where the reinforcing steel does not cross from one beam to another or from one beam to the slabs or columns adjacent to it and vice versa, except for a few centimeters, which makes the basic building elements of columns, slabs and beams They all work in isolation from each other and from the environment surrounding them from all sides. This traditional method of reinforcement may be valid and lasting in geographical areas that are not exposed to earthquakes and earthquakes, where all the loads and tensile forces in the building are constantly directed vertically downward due to gravity and are borne directly by the vertical reinforcement of the building. However, in the case of earthquakes and earthquakes, the loads and tensile forces in the building shift from the vertical direction to the horizontal direction at an angle of inclination that depends on the strength of the earthquake, and most of them are borne by the horizontal reinforcement extending between the basic elements of the building, such as columns, slabs and beams, and since the crossing of the reinforcement between each of the columns, slabs and beams between them And each other, and vice versa, does not exceed several centimeters. In any case, the tensile strength, cohesion and bonding between the various parts of the building are very weak, which causes the buildings to disintegrate and collapse in the horrific manner that we saw in the earthquake in Turkey and Syria in February 2023, which caused the collapse of tens of thousands of buildings in A few seconds later, it left more than 50,000 dead, hundreds of thousands injured, and millions displaced. Description of the new earthquake-resistant model: The idea of the new model in the reinforcement of concrete buildings and constructions is based on the theory that we have formulated as follows: [The tensile strength, cohesion and bonding between the basic parts of the concrete building (columns, beams and slabs) increases as the lengths of the reinforcing steel bars increase and they extend and branch and the different parts of the building share them with each other.] . In other words, the strength, solidity, and cohesion of concrete buildings increase and they become resistant to earthquakes as the lengths of the reinforcing steel bars increase, extend, branch, and share with the various parts of the building, such as columns, beams, and slabs. That is, the reinforcing skewers of the columns must extend in their lengths without cutting to cross from one floor to another until their end. Likewise, the reinforcing skewers of the beams must extend in their lengths without cutting to cross from one beam to another. The ends of these skewers must rest at the bottom of the columns adjacent to the beams. The same thing applies to the reinforcing skewers of the slabs where they must These skewers should be extended in their lengths without cutting to cross from one tile to another, and the ends of these skewers should rest either under the adjacent columns or inside the beams adjacent to the slabs as follows: First, reinforce the columns: The columns have the lion's share of the reinforcing steel in this model in terms of type and quantity, as the columns contain two types of reinforcing bars. The first type is large-diameter bars that emerge from the base of the building, which are the nerves of the column. These bars must extend over their normal length of 12 meters or more and extend to a height of three floors, if desired. In raising other floors, bars with the same diameter and the same length are added to the top after the second floor. The second type is bars with a smaller diameter, and they are the same ones that are used to reinforce beams and slabs, so that the bars that reinforce the beams and slabs facing each column are bent down inside this column and along the entire length of the column. This requires an order. Most engineers do not prefer it, which is to pour the entire columns and pour the roof at once, but we prefer this method because it enables us to extend the reinforcing bars of both the beams and slabs to the bottom of the columns so that the entire building becomes one concrete block that is cohesive and resistant to earthquakes. Secondly, arming the cameras: The beams' reinforcing skewers must also extend to a full length of 12 meters or more without cutting. The ends of the skewers are bent and dropped inside the column at the beginning of the beam to its bottom. Then the skewers are extended inside the beam so that their other end falls under the facing column at the end of the beam. The skewers may cross over the head of a column. Another passes through another adjacent beam and rests at the bottom of a third column, according to the lengths of each of the skewers and beams. Third, reinforcement of slabs: The slab reinforcing skewers must also extend their entire length, 12 meters or more, without cutting, distinguishing between two cases. The first case is the skewers opposite the columns, and their ends are dropped inside one of the columns. Then the skewers cross inside the adjacent slab and their other end falls below the opposite column. The skewers may cross over The head of the adjacent column passes through another adjacent slab and rests at the bottom of a third column, according to the dimensions of the slabs and the lengths of the skewers. The second case is the skewers opposite the beams, and their ends must be bent in the form of a square or rectangle according to the dimensions of the beam’s width and height, and this square or rectangle is dropped inside the beam at the beginning of the slab, and it serves as The skewers are for the beams, then the skewers are extended along the length of the slab, and at the end of the slab, the skewers are bent down to the bottom of the adjacent beam in the shape of the letter U, after which the skewers are extended inside the adjacent slab, and this is repeated in the same way inside the other adjacent beams until the end of the skewer, then it is bent downward in the form of a square or rectangle inside the beam, as happened. In its beginning.

Keywords: earthquake resistant buildings, earthquake resistant concrete constructions, new technology for reinforcement of concrete buildings, new technology in concrete reinforcement

Procedia PDF Downloads 58

Authors: Mukul Sharma, Madhusmita Das, Sundeep Chaitanya Vedithi

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Leprosy is a chronic human disease caused by Mycobacterium leprae, that cannot be cultured in vitro. Though treatable with multidrug therapy (MDT), recently, bacteria reported resistance to multiple antibiotics. Targeting DNA replication and repair pathways can serve as the foundation of developing new anti-leprosy drugs. Due to the absence of an axenic culture medium for the propagation of M. leprae, studying cellular processes, especially those belonging to DNA repair pathways, is challenging. Genomic understanding of M. Leprae harbors several protein-coding genes with no previously assigned function known as 'hypothetical proteins'. Here, we report identification and expression of known and hypothetical DNA repair genes from a human skin biopsy and mouse footpads that are involved in base excision repair, direct reversal repair, and SOS response. Initially, a bioinformatics approach was employed based on sequence similarity, identification of known protein domains to screen the hypothetical proteins in the genome of M. leprae, that are potentially related to DNA repair mechanisms. Before testing on clinical samples, pure stocks of bacterial reference DNA of M. leprae (NHDP63 strain) was used to construct standard graphs to validate and identify lower detection limit in the qPCR experiments. Primers were designed to amplify the respective transcripts, and PCR products of the predicted size were obtained. Later, excisional skin biopsies of newly diagnosed untreated, treated, and drug resistance leprosy cases from SIHR & LC hospital, Vellore, India were taken for the extraction of RNA. To determine the presence of the predicted transcripts, cDNA was generated from M. leprae mRNA isolated from clinically confirmed leprosy skin biopsy specimen across all the study groups. Melting curve analysis was performed to determine the integrity of the amplification and to rule out primer‑dimer formation. The Ct values obtained from qPCR were fitted to standard curve to determine transcript copy number. Same procedure was applied for M. leprae extracted after processing a footpad of nude mice of drug sensitive and drug resistant strains. 16S rRNA was used as positive control. Of all the 16 genes involved in BER, DR, and SOS, differential expression pattern of the genes was observed in terms of Ct values when compared to human samples; this was because of the different host and its immune response. However, no drastic variation in gene expression levels was observed in human samples except the nth gene. The higher expression of nth gene could be because of the mutations that may be associated with sequence diversity and drug resistance which suggests an important role in the repair mechanism and remains to be explored. In both human and mouse samples, SOS system – lexA and RecA, and BER genes AlkB and Ogt were expressing efficiently to deal with possible DNA damage. Together, the results of the present study suggest that DNA repair genes are constitutively expressed and may provide a reference for molecular diagnosis, therapeutic target selection, determination of treatment and prognostic judgment in M. leprae pathogenesis.

Keywords: DNA repair, human biopsy, hypothetical proteins, mouse footpads, Mycobacterium leprae, qPCR

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Authors: Fatma Acheuk, Akila Hamichi, Siham Semmar

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The crude ethanolic extract from Solenostemma argel was obtained by maceration of leaves and stems of the plant. Phytochimical study revealed the richness of the species on flavonoids, alkaloids, tannins and glycosides. Antimicrobial activity of the growth of clinical isolates of Eschirichia coli, Pseudomonas aeriginosa, Staphylococus aureus and Bacillus Subtilis was carried out using agar disc diffusion. The results of the study revealed that the test compound has antimicrobial activity against gram-positive bacteria which are resistant to commonly antimicrobial agents used. However, no effect was observed on other species tested.

Keywords: Solenostemma argel, crude extract, phytochemical screening, antimicrobial activity

Procedia PDF Downloads 368

Authors: H.Yari, M. Mohseni, Z. Ranjbar

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In this work a typical automotive clearcoat is modified with a combination of hyperbranched polymer (HBP) and polyhedral oligomeric silsesquioxane (POSS) nanostructures to simultaneously enhance the scratch resistance and healing ability of the resulting films. Micro-scratch and healing data revealed that these goals were achieved at high loadings of modifiers. Enhanced scratch resistance was attributed to the improved elastic recovery of the clearcoats in presence of modifiers. In addition, improved healing performance due to the partial replacement of covalent cross-links with physical ones resulted from the unique globular highly branched structure of HBP and POSS macromolecules.

Keywords: automotive clearcoat, POSS building blocks scratch resistance, self-healing

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Authors: Sukrat Sinha, Abhay Kumar, Shanthy Sundaram

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The Leishmania homologue of activated C kinase (LACK) is known T cell epitope from soluble Leishmania antigens (SLA) that confers protection against Leishmania challenge. This antigen has been found to be highly conserved among Leishmania strains. LACK has been shown to be protective against L. donovani challenge. A comprehensive analysis of several LACK sequences was completed. The analysis shows a high level of conservation, lower variability and higher antigenicity in specific portions of the LACK protein. This information provides insights for the potential consideration of LACK as a putative candidate in the context of visceral Leishmaniasis vaccine target.

Keywords: bioinformatics, genome assembly, leishmania activated protein kinase c (lack), next-generation sequencing

Procedia PDF Downloads 330

Authors: Zakia Hbellaq

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The Mediterranean region is considered a hotbed for climate change. Morocco is a semi-arid Mediterranean country facing water shortages and poor water quality. Its limited water resources limit the activities of various economic sectors. Most of Morocco's territory is in arid and desert areas. The potential water resources are estimated at 22 billion m3, which is equivalent to about 700 m3/inhabitant/year, and Morocco is in a state of structural water stress. Strictly speaking, the Kingdom of Morocco is one of the “very riskiest” countries, according to the World Resources Institute (WRI), which oversees the calculation of water stress risk in 167 countries. The surprising results of the Institute (WRI) rank Morocco as one of the riskiest countries in terms of water scarcity, ranking 3.89 out of 5, thus occupying the 23rd place out of a total of 167 countries, which indicates that the demand for water exceeds the available resources. Agriculture with a score of 3.89 is most affected by water stress from irrigation and places a heavy burden on the water table. Irrigation is an unavoidable technical need and has undeniable economic and social benefits given the available resources and climatic conditions. Irrigation, and therefore the agricultural sector, currently uses 86% of its water resources, while industry uses 5.5%. Although its development has undeniable economic and social benefits, it also contributes to the overfishing of most groundwater resources and the surprising decline in levels and deterioration of water quality in some aquifers. In this context, REUSE is one of the proposed solutions to reduce the water footprint of the agricultural sector and alleviate the shortage of water resources. Indeed, wastewater reuse, also known as REUSE (reuse of treated wastewater), is a step forward not only for the circular economy but also for the future, especially in the context of climate change. In particular, water reuse provides an alternative to existing water supplies and can be used to improve water security, sustainability, and resilience. However, given the introduction of organic trace pollutants or, organic micro-pollutants, the absorption of emerging contaminants, and decreasing salinity, it is possible to tackle innovative capabilities to overcome these problems and ensure food and health safety. To this end, attention will be paid to the adoption of an integrated and attractive approach, based on the reinforcement and optimization of the treatments proposed for the elimination of the organic load with particular attention to the elimination of emerging pollutants, to achieve this goal. , membrane bioreactors (MBR) as stand-alone technologies are not able to meet the requirements of WHO guidelines. They will be combined with heterogeneous Fenton processes using persulfate or hydrogen peroxide oxidants. Similarly, adsorption and filtration are applied as tertiary treatment In addition, the evaluation of crop performance in terms of yield, productivity, quality, and safety, through the optimization of Trichoderma sp strains that will be used to increase crop resistance to abiotic stresses, as well as the use of modern omics tools such as transcriptomic analysis using RNA sequencing and methylation to identify adaptive traits and associated genetic diversity that is tolerant/resistant/resilient to biotic and abiotic stresses. Hence, ensuring this approach will undoubtedly alleviate water scarcity and, likewise, increase the negative and harmful impact of wastewater irrigation on the condition of crops and the health of their consumers.

Keywords: water scarcity, food security, irrigation, agricultural water footprint, reuse, emerging contaminants

Procedia PDF Downloads 141

Authors: Gousilin Leandra Rocha Da Silva, Stéfani T. A. Dantas, Bruna F. Rossi, Erika R. Bonsaglia, Ivana G. Castilho, Terue Sadatsune, Ary Fernandes Júnior, Vera l. M. Rall

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Kidney failure causes decreased diuresis and accumulation of nitrogenous substances in the body. To increase patient survival, hemodialysis is used as a partial substitute for renal function. However, contamination of the water used in this treatment, causing bacteremia in patients, is a worldwide concern. The Burkholderia cepacia complex (Bcc), a group of bacteria with more than 20 species, is frequently isolated from hemodialysis water samples and comprises opportunistic bacteria, affecting immunosuppressed patients, due to its wide variety of virulence factors, in addition to innate resistance to several antimicrobial agents, contributing to the permanence in the hospital environment and to the pathogenesis in the host. The objective of the present work was to characterize molecularly and phenotypically Bcc isolates collected from the water and dialysate of the Hemodialysis Unit and from the blood of patients at a Public Hospital in Botucatu, São Paulo, Brazil, between 2019 and 2021. We used 33 Bcc isolates, previously obtained from blood cultures from patients with bacteremia undergoing hemodialysis treatment (2019-2021) and 24 isolates obtained from water and dialysate samples in a Hemodialysis Unit (same period). The recA gene was sequenced to identify the specific species among the Bcc group. All isolates were tested for the presence of some genes that encode virulence factors such as cblA, esmR, zmpA and zmpB. Considering the epidemiology of the outbreak, the Bcc isolates were molecularly characterized by Multi Locus Sequence Type (MLST) and by pulsed-field gel electrophoresis (PFGE). The verification and quantification of biofilm in a polystyrene microplate were performed by submitting the isolates to different incubation temperatures (20°C, average water temperature and 35°C, optimal temperature for group growth). The antibiogram was performed with disc diffusion tests on agar, using discs impregnated with cefepime (30µg), ceftazidime (30µg), ciprofloxacin (5µg), gentamicin (10µg), imipenem (10µg), amikacin 30µg), sulfametazol/trimethoprim (23.75/1.25µg) and ampicillin/sulbactam (10/10µg). The presence of ZmpB was identified in all isolates, while ZmpA was observed in 96.5% of the isolates, while none of them presented the cblA and esmR genes. The antibiogram of the 33 human isolates indicated that all were resistant to gentamicin, colistin, ampicillin/sulbactam and imipenem. 16 (48.5%) isolates were resistant to amikacin and lower rates of resistance were observed for meropenem, ceftazidime, cefepime, ciprofloxacin and piperacycline/tazobactam (6.1%). All isolates were sensitive to sulfametazol/trimethoprim, levofloxacin and tigecycline. As for the water isolates, resistance was observed only to gentamicin (34.8%) and imipenem (17.4%). According to PFGE results, all isolates obtained from humans and water belonged to the same pulsotype (1), which was identified by recA sequencing as B. cepacia¸, belonging to sequence type ST-767. By observing a single pulse type over three years, one can observe the persistence of this isolate in the pipeline, contaminating patients undergoing hemodialysis, despite the routine disinfection of water with peracetic acid. This persistence is probably due to the production of biofilm, which protects bacteria from disinfectants and, making this scenario more critical, several isolates proved to be multidrug-resistant (resistance to at least three groups of antimicrobials), turning the patient care even more difficult.

Keywords: hemodialysis, burkholderia cepacia, PFGE, MLST, multi drug resistance

Procedia PDF Downloads 87

Authors: Ramachandran Manivannan, B. Sakthi Swaroop, Selvam Noyel Victoria

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Microbial corrosion of brass gauze by the aerobic film forming bacteria Arthrobacter sulfurous in neutral media was investigated using gravimetric studies. Maximum weight loss of 166.98 mg was observed for a period of 28 days of exposure to the bacterial medium as against the weight loss of 13.69 mg for control. The optical density studies for the bacterial culture was found to show attainment of stationary phase in 48 h. Scanning electron microscopy analysis of the samples shows the presence of pitting corrosion. The energy dispersive X-ray analysis of the samples showed increased oxygen and phosphorus content in the sample due to bacterial activity.

Keywords: Arthrobacter sulfureus, biocorrosion, brass, neutral medium

Procedia PDF Downloads 163

Authors: Veenu Bala, Yashpal S. Chhonker, Bhavana Kushwaha, Rabi S. Bhatta, Gopal Gupta, Vishnu L. Sharma

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According to UNAIDS 2013 estimate nearly 52% of all individuals living with HIV are now women of reproductive age (15–44 years). Seventy-five percent cases of HIV acquisition are through heterosexual contacts and sexually transmitted infections (STIs), attributable to unsafe sexual behaviour. Each year, an estimated 500 million people acquire atleast one of four STIs: chlamydia, gonorrhoea, syphilis and trichomoniasis. Trichomonas vaginalis (TV) is exclusively sexually transmitted in adults, accounting for 30% of STI cases and associated with pelvic inflammatory disease (PID), vaginitis and pregnancy complications in women. TV infection resulted in impaired vaginal milieu, eventually favoring HIV transmission. In the absence of an effective prophylactic HIV vaccine, prevention of new infections has become a priority. It was thought worthwhile to integrate HIV prevention and reproductive health services including unintended pregnancy protection for women as both are related with unprotected sex. Initially, nonoxynol-9 (N-9) had been proposed as a spermicidal agent with microbicidal activity but on the contrary it increased HIV susceptibility due to surfactant action. Thus, to accomplish an urgent need of novel woman controlled non-detergent microbicidal spermicides benzenepropanamine analogues have been synthesized. At first, five benzenepropanamine-dithiocarbamate hybrids have been synthesized and evaluated for their spermicidal, anti-Trichomonas and anti-fungal activities along with safety profiling to cervicovaginal cells. In order to further enhance the scope of above study benzenepropanamine was hybridized with thiourea as to introduce anti-HIV potential. The synthesized hybrid molecules were evaluated for their reverse transcriptase (RT) inhibition, spermicidal, anti-Trichomonas and antimicrobial activities as well as their safety against vaginal flora and cervical cells. simulated vaginal fluid (SVF) stability and pharmacokinetics of most potent compound versus N-9 was examined in female Newzealand (NZ) rabbits to observe its absorption into systemic circulation and subsequent exposure in blood plasma through vaginal wall. The study resulted in the most promising compound N-butyl-4-(3-oxo-3-phenylpropyl) piperazin-1-carbothioamide (29) exhibiting better activity profile than N-9 as it showed RT inhibition (72.30 %), anti-Trichomonas (MIC, 46.72 µM against MTZ susceptible and MIC, 187.68 µM against resistant strain), spermicidal (MEC, 0.01%) and antifungal activity (MIC, 3.12–50 µg/mL) against four fungal strains. The high safety against vaginal epithelium (HeLa cells) and compatibility with vaginal flora (lactobacillus), SVF stability and least vaginal absorption supported its suitability for topical vaginal application. Docking study was performed to gain an insight into the binding mode and interactions of the most promising compound, N-butyl-4-(3-oxo-3-phenylpropyl) piperazin-1-carbothioamide (29) with HIV-1 Reverse Transcriptase. The docking study has revealed that compound (29) interacted with HIV-1 RT similar to standard drug Nevirapine. It may be concluded that hybridization of benzenepropanamine and thiourea moiety resulted into novel lead with multiple activities including RT inhibition. A further lead optimization may result into effective vaginal microbicides having spermicidal, anti-Trichomonas, antifungal and anti-HIV potential altogether with enhanced safety to cervico-vaginal cells in comparison to Nonoxynol-9.

Keywords: microbicidal, nonoxynol-9, reverse transcriptase, spermicide

Procedia PDF Downloads 337

Authors: Sajeli A. Begum, Ameer Basha, Kirti Hira, Rukaiyya Khan

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Cyclic dipeptides are simple diketopiperazine derivatives being investigated by several scientists for their biological effects which include anticancer, antimicrobial, haematological, anticonvulsant, immunomodulatory effect, etc. They are potentially active microbial metabolites having been synthesized too, for developing into drug candidates. Cultures of Pseudomonas species have earlier been reported to produce cyclic dipeptides, helping in quorum sensing signals and bacterial–host colonization phenomena during infections, causing cell anti-proliferation and immunosuppression. Fluorescing Pseudomonas species have been identified to secrete lipid derivatives, peptides, pyrroles, phenazines, indoles, aminoacids, pterines, pseudomonic acids and some antibiotics. In the present work, results of investigation on the cyclic dipeptide metabolites secreted by the culture broth of Pseudomonas species as potent pro-inflammatory cytokine inhibitors are discussed. The bacterial strain was isolated from the rhizospheric soil of groundnut crop and identified as Pseudomonas aeruginosa by 16S rDNA sequence (GenBank Accession No. KT625586). Culture broth of this strain was prepared by inoculating into King’s B broth and incubating at 30 ºC for 7 days. The ethyl acetate extract of culture broth was prepared and lyophilized to get a dry residue (EEPA). Lipopolysaccharide (LPS)-induced ELISA assay proved the inhibition of tumor necrosis factor-alpha (TNF-α) secretion in culture supernatant of RAW 264.7 cells by EEPA (IC50 38.8 μg/mL). The effect of oral administration of EEPA on plasma TNF-α level in rats was tested by ELISA kit. The LPS mediated plasma TNF-α level was reduced to 45% with 125 mg/kg dose of EEPA. Isolation of the chemical constituents of EEPA through column chromatography yielded ten cyclic dipeptides, which were characterized using nuclear magnetic resonance and mass spectroscopic techniques. These cyclic dipeptides are biosynthesized in microorganisms by multifunctional assembly of non-ribosomal peptide synthases and cyclic dipeptide synthase. Cyclo (Gly-L-Pro) was found to be more potentially (IC50 value 4.5 μg/mL) inhibiting TNF-α production followed by cyclo (trans-4-hydroxy-L-Pro-L-Phe) (IC50 value 14.2 μg/mL) and the effect was equal to that of standard immunosuppressant drug, prednisolone. Further, the effect was analyzed by determining mRNA expression of TNF-α in LPS-stimulated RAW 264.7 macrophages using quantitative real-time reverse transcription polymerase chain reaction. EEPA and isolated cyclic dipeptides demonstrated diminution of TNF-α mRNA expression levels in a dose-dependent manner under the tested conditions. Also, they were found to control the expression of other pro-inflammatory cytokines like IL-1β and IL-6, when tested through their mRNA expression levels in LPS-stimulated RAW 264.7 macrophages under LPS-stimulated conditions. In addition, significant inhibition effect was found on Nitric oxide production. Further all the compounds exhibited weak toxicity to LPS-induced RAW 264.7 cells. Thus the outcome of the study disclosed the effectiveness of EEPA and the isolated cyclic dipeptides in down-regulating key cytokines involved in pathophysiology of autoimmune diseases.In another study led by the investigators, microbial cyclic dipeptides were found to exhibit excellent antimicrobial effect against Fusarium moniliforme which is an important causative agent of Sorghum grain mold disease. Thus, cyclic dipeptides are emerging small molecular drug candidates for various autoimmune diseases.

Keywords: cyclic dipeptides, cytokines, Fusarium moniliforme, Pseudomonas, TNF-alpha

Procedia PDF Downloads 205

Authors: Sayed M. Ahmed, Sawsan S. Darwish, Nagib A. Elmarzugi, Mohammad A. Al-Dosari, Mahmoud A. Adam, Nadia A. Al-Mouallimi

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Historical stone surfaces and architectural heritage may undergo unwanted changes due to the exposure to many physical and chemical deterioration factors, the innovative properties of the nano - materials can have advantageous application in the restoration and conservation of the cultural heritage with relation to the tailoring of new products for protection and consolidation of stone. The current work evaluates the effectiveness of inorganic compatible treatments; based on nanosized particles of silica (SiO2) dispersed in silicon based product, commonly used as a water-repellent/ consolidation for the construction materials affected by different kinds of decay. The nanocomposites obtained by dispersing the silica nanoparticles in polymeric matrices SILRES® BS OH 100 (solventless mixtures of ethyl silicates), in order to obtain a new nanocomposite, with hydrophobic and consolidation properties, to improve the physical and mechanical properties of the stone material. The nanocomposites obtained and pure SILRES® BS OH 100 were applied by brush Experimental stone blocks. The efficacy of the treatments has been evaluated after consolidation and artificial Thermal aging, through capillary water absorption measurements, Ultraviolet-light exposure to evaluate photo-induced and the hydrophobic effects of the treated surface, Scanning electron microscopy (SEM) examination is performed to evaluate penetration depth, re-aggregating effects of the deposited phase and the surface morphology before and after artificialaging. Sterio microscopy investigation is performed to evaluate the resistant to the effects of the erosion, acids and salts. Improving of stone mechanical properties were evaluated by compressive strength tests, colorimetric measurements were used to evaluate the optical appearance. All the results get together with the apparent effect that, silica/polymer nanocomposite is efficient material for the consolidation of artistic and architectural sandstone monuments, completely compatible, enhanced the durability of sandstone toward thermal and UV aging. In addition, the obtained nanocomposite improved the stone mechanical properties and the resistant to the effects of the erosion, acids and salts compared to the samples treated with pure SILRES® BS OH 100 without silica nanoparticles.

Keywords: colorimetric measurements, compressive strength, nanocomposites, porous stone consolidation, silica nanoparticles, sandstone

Procedia PDF Downloads 245

Authors: Basavaraj Vadavadagi, Satishkumar Shekhawat

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Interstitial free steels posses better formability and have many applications in automotive industries. Forming limit diagrams (FLDs) indicate the formability of materials which can be determined by experimental and finite element (FE) simulations. FLDs were determined experimentally by LDH test, utilizing optical strain measurement system for measuring the strains in different width specimens and by FE simulations in Interstitial Free (IF) and Interstitial Free High Strength (IFHS) steels. In this study, the experimental and FE simulated FLDs are compared and also the stress based FLDs were investigated.

Keywords: forming limit diagram, limiting dome height, optical strain measurement, interstitial

Procedia PDF Downloads 220

Authors: Harold M. Carag, April Charmaine D. Camacho, Girlie Nora A. Abrigo, Florencia G. Palis, Ma. Larissa Lelu P. Gata

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A technology impact assessment on the use of microbial inoculants in the reforestation and rehabilitation of forest ancestral lands of the Magbukün Aytas in Morong, Bataan was conducted. This two-year rainforestation technology aimed to determine the optimum condition for the improvement of seedling survival rate in the nursery and in the field to hasten the process of forest regeneration of Magbukün Ayta’s ancestral land. A combination of qualitative methods (key informant interviews, focus groups and participant observation), participated by the farmers who were directly involved in the project, community men and women, the council of elders and the project staff, was employed to complete this impact assessment. The recorded data were transcribed, and the accounts were broadly categorized on the following aspects: social (gender, institutional, anthropological), economic and environmental. The Australian Center for International Agricultural Research (ACIAR) framework was primarily used for the impact analysis while the Harvard Analytical Framework was specifically used for the gender impact analysis. Through this technology, a wildling nursery with more than one thousand seedlings was successfully established and served as a good area for the healthy growth of seedlings that would be planted in the forest. Results showed that this technology affected positively and negatively the various gender roles present in the community although household work remained to be the women’s responsibility. The technology introduced directly added up to the workload done by the men and women (preparing and applying fertilizer, making pots etc.) but this, in turn, provided ways to increase their sources of livelihood. The gender roles that were already present were further strengthened after the project and men remained to be in control. The technology or project in turn also benefited from the already present roles since they no longer have to assign things to them, the execution of the various roles was smoothly executed. In the anthropological aspect, their assigned task to manage the nursery was an easy responsibility because of their deep connection to the environment and their fear and beliefs on ‘engkato’ and ‘anito’ was helpful in guarding the forest. As the cultural value of these trees increases, their mindset of safeguarding the forest also heightens. Meanwhile, the welfare of the whole tribe is the ultimate determinant of the swift entry of projects. The past institutions brought ephemeral reliefs on the subsistence of the Magbukün Aytas. These were good ‘conditioning’ factors for the adoption of the technology of the project. As an attempt to turn away from the dependent of harmful chemical, the project’s way of introducing organic inputs was slowly gaining popularity in the community. Economically, the project was able to provide additional income to the farmers. However, the slow mode of payment dismayed other farmers and abandoned their roles. Lastly, major environmental effects weren’t that much observed after the application of the technology. The minor effects concentrated more on the improved conditions of the soil and water in the community. Because of the introduced technology, soil conditions became more favorable specifically for the species that were planted. The organic fertilizers used were in turn not harmful for the residents living in Sitio Kanawan. There were no human diseases caused by the technology. The conservation of the biodiversity of the forest is clearly the most evident long-term result of the project.

Keywords: ancestral lands, impact assessment, microbial inculants, reforestation

Procedia PDF Downloads 130

Authors: M. Maleczek, Leszek Bogdan, Kazimierz Drabczyk, Agnieszka Iwan

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Crystalline silicon (Si) solar cells are the main product in the market among the various photovoltaic technologies concerning such advantages as: material richness, high carrier mobilities, broad spectral absorption range and established technology. However, photovoltaic technology on the stiff substrates are heavier, more fragile and less cost-effective than devices on the flexible substrates to be applied in special applications. The main goal of our work was to incorporate silicon solar cells into various fabric, without any change of the electrical and mechanical parameters of devices. This work is realized for the GEKON project (No. GEKON2/O4/268473/23/2016) sponsored by The National Centre for Research and Development and The National Fund for Environmental Protection and Water Management. In our work, the polyamide or polyester fabrics were used as a flexible substrate in the created devices. Applied fabrics differ in tensile and tear strength. All investigated polyamide fabrics are resistant to weathering and UV, while polyester ones is resistant to ozone, water and ageing. The examined fabrics are tight at 100 cm water per 2 hours. In our work, commercial silicon solar cells with the size 156 × 156 mm were cut into nine parts (called single solar cells) by diamond saw and laser. Gap and edge after cutting of solar cells were checked by transmission electron microscope (TEM) to study morphology and quality of the prepared single solar cells. Modules with the size of 160 × 70 cm (containing about 80 single solar cells) were created and investigated by electrical and mechanical methods. Weight of constructed module is about 1.9 kg. Three types of solar cell architectures such as: -fabric/EVA/Si solar cell/EVA/film for lamination, -backsheet PET/EVA/Si solar cell/EVA/film for lamination, -fabric/EVA/Si solar cell/EVA/tempered glass, were investigated taking into consideration type of fabric and lamination process together with the size of solar cells. In investigated devices EVA, it is ethylene-vinyl acetate, while PET - polyethylene terephthalate. Depend on the lamination process and compatibility of textile with solar cell an efficiency of investigated flexible silicon solar cells was in the range of 9.44-16.64 %. Multi folding and unfolding of flexible module has no impact on its efficiency as was detected by Instron equipment. Power (P) of constructed solar module is 30 W, while voltage about 36 V. Finally, solar panel contains five modules with the polyamide fabric and tempered glass will be produced commercially for different applications (dual use).

Keywords: flexible devices, mechanical properties, silicon solar cells, textiles

Procedia PDF Downloads 168

Authors: A. Siham Dehmani, B. Djamal Zerrouki

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Domestic wastewater contains high concentrations of nitrogen, which can affect public health and cause harmful ecological impacts. The potential of microalgae as a source of renewable energy based on wastewater has received increasing interest worldwide in recent decades. The microalgae cultivation in wastewater has two advantages: wastewater treatment and algal biomass production. Our work aimed to remove nitrogen from municipal wastewater. Wastewater samples were taken from the wastewater treatment station located in Ouargla and used as a medium for the cultivation of chlorella microalgae strains inside a photobioreactor. Analysis of different parameters was done every 2 days along the period of the cultivation (10 days). The average removal efficiencies of nitrogen were maintained at 95%. Our results show the potential of integrating nutrient removal from wastewater by microalgae as a secondary wastewater treatment processes.

Keywords: biomass, microalgae, treatment, wastewater

Procedia PDF Downloads 410

Authors: E. Nakamachi, K. Matsumoto, K. Yamamoto, Y. Morita, H. Sakamoto

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In recently, electromagnetic and mechanical stimulations have been recognized as the effective extracellular environment stimulation technique to enhance the defected peripheral nerve tissue regeneration. In this study, we developed a new hybrid bioreactor by adopting 50 Hz uniform alternative current (AC) magnetic stimulation and 4% strain mechanical stimulation. The guide tube for nerve regeneration is mesh structured tube made of biodegradable polymer, such as polylatic acid (PLA). However, when neural damage is large, there is a possibility that peripheral nerve undergoes necrosis. So it is quite important to accelerate the nerve tissue regeneration by achieving enhancement of nerve axonal extension rate. Therefore, we try to design and fabricate the system that can simultaneously load the uniform AC magnetic field stimulation and the stretch stimulation to cells for enhancement of nerve axonal extension. Next, we evaluated systems performance and the effectiveness of each stimulation for rat adrenal pheochromocytoma cells (PC12). First, we designed and fabricated the uniform AC magnetic field system and the stretch stimulation system. For the AC magnetic stimulation system, we focused on the use of pole piece structure to carry out in-situ microscopic observation. We designed an optimum pole piece structure using the magnetic field finite element analyses and the response surface methodology. We fabricated the uniform AC magnetic field stimulation system as a bio-reactor by adopting analytically determined design specifications. We measured magnetic flux density that is generated by the uniform AC magnetic field stimulation system. We confirmed that measurement values show good agreement with analytical results, where the uniform magnetic field was observed. Second, we fabricated the cyclic stretch stimulation device under the conditions of particular strains, where the chamber was made of polyoxymethylene (POM). We measured strains in the PC12 cell culture region to confirm the uniform strain. We found slightly different values from the target strain. Finally, we concluded that these differences were allowable in this mechanical stimulation system. We evaluated the effectiveness of each stimulation to enhance the nerve axonal extension using PC12. We confirmed that the average axonal extension length of PC12 under the uniform AC magnetic stimulation was increased by 16 % at 96 h in our bio-reactor. We could not confirm that the axonal extension enhancement under the stretch stimulation condition, where we found the exfoliating of cells. Further, the hybrid stimulation enhanced the axonal extension. Because the magnetic stimulation inhibits the exfoliating of cells. Finally, we concluded that the enhancement of PC12 axonal extension is due to the magnetic stimulation rather than the mechanical stimulation. Finally, we confirmed that the effectiveness of the uniform AC magnetic field stimulation for the nerve axonal extension using PC12 cells.

Keywords: nerve cell PC12, axonal extension, nerve regeneration, electromagnetic-mechanical stimulation, bioreactor

Procedia PDF Downloads 261

Authors: Matthew C. Best

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Linear Multi-Input Multi-Output (MIMO) dynamic models can be identified, with no a priori knowledge of model structure or order, using a new Generalised Identifying Filter (GIF). Based on an Extended Kalman Filter, the new filter identifies the model iteratively, in a continuous modal canonical form, using only input and output time histories. The filter’s self-propagating state error covariance matrix allows easy determination of convergence and conditioning, and by progressively increasing model order, the best fitting reduced-order model can be identified. The method is shown to be resistant to noise and can easily be extended to identification of smoothly nonlinear systems.

Keywords: system identification, Kalman filter, linear model, MIMO, model order reduction

Procedia PDF Downloads 588

Authors: Nayif Alrasheedi, Sultan Almutairi

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Field-wide, a water supply wells’ downhole corrosion inhibition program is being applied to maintain downhole component integrity and keep the fluid corrosivity below 5 MPY. Batch treatment is currently used to inject the oil field chemical. This work is a case study consisting of analytical procedures used to optimize the frequency of the good corrosion inhibition treatments. During the study, a corrosion cell was fitted with a special three-electrode configuration for electrochemical measurements, electrochemical linear polarization, corrosion monitoring, and microbial analysis. This study revealed that the current practice is not able to mitigate material corrosion in the downhole system for more than three months.

Keywords: downhole corrosion inhibition, electrochemical measurements, electrochemical linear polarization, corrosion monitoring

Procedia PDF Downloads 165

Authors: Eliane G. Tótoli, Hérida Regina N. Salgado

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Daptomycin is an important antimicrobial agent used in clinical practice nowadays, since it is very active against some Gram-positive bacteria that are particularly challenges for the medicine, such as methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococci (VRE). The importance of environmental preservation has receiving special attention since last years. Considering the evident need to protect the natural environment and the introduction of strict quality requirements regarding analytical procedures used in pharmaceutical analysis, the industries must seek environmentally friendly alternatives in relation to the analytical methods and other processes that they follow in their routine. In view of these factors, green analytical chemistry is prevalent and encouraged nowadays. In this context, infrared spectroscopy stands out. This is a method that does not use organic solvents and, although it is formally accepted for the identification of individual compounds, also allows the quantitation of substances. Considering that there are few green analytical methods described in literature for the analysis of daptomycin, the aim of this work was the development and validation of a green analytical method for the quantification of this drug in lyophilized powder for injectable solution, by Fourier-transform infrared spectroscopy (FT-IR). Method: Translucent potassium bromide pellets containing predetermined amounts of the drug were prepared and subjected to spectrophotometric analysis in the mid-infrared region. After obtaining the infrared spectrum and with the assistance of the IR Solution software, quantitative analysis was carried out in the spectral region between 1575 and 1700 cm-1, related to a carbonyl band of the daptomycin molecule, and this band had its height analyzed in terms of absorbance. The method was validated according to ICH guidelines regarding linearity, precision (repeatability and intermediate precision), accuracy and robustness. Results and discussion: The method showed to be linear (r = 0.9999), precise (RSD% < 2.0), accurate and robust, over a concentration range from 0.2 to 0.6 mg/pellet. In addition, this technique does not use organic solvents, which is one great advantage over the most common analytical methods. This fact contributes to minimize the generation of organic solvent waste by the industry and thereby reduces the impact of its activities on the environment. Conclusion: The validated method proved to be adequate to quantify daptomycin in lyophilized powder for injectable solution and can be used for its routine analysis in quality control. In addition, the proposed method is environmentally friendly, which is in line with the global trend.

Keywords: daptomycin, Fourier-transform infrared spectroscopy, green analytical chemistry, quality control, spectrometry in IR region

Procedia PDF Downloads 372