Search results for: dose reduction

Authors: Shiva Emami, Jenny Persson, Bengt Johansson Lindbom

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Group A streptococcus (GAS) is a prevalent human pathogen, causing a wide range of infections and diseases. One of the most well-known virulence factors in GAS is M protein, a surface protein that facilitates bacterial invasion. In this study, we used a recombinant GAS strain (GAS-2W) expressing M protein containing a hyper immunogenic peptide (2W). Mice were immunized three times with heat-killed-GAS subcutaneously at three weeks intervals. Three weeks post last immunization, mice were challenged intraperitoneally with a lethal dose of live GAS. In order to investigate the impact of IFN-ƴ and antibodies in protection against GAS infection, we used a mouse model knock-out for IFN-ƴ (IFN-ƴ KO). We observed immunization with GAS-2W strain can increase protection against GAS infection in mice compared with the original GAS strain. Higher levels of antibodies against M1 protein were measured in GAS-2W-immunized mice. There was also a significant increase in IgG2c response in mice immunized with GAS2W. By using IFN-ƴ KO mice, we showed that not a high level of total IgG, but IgG2c was correlated with protection through the i.p challenge. It also emphasizes the importance of IFN-ƴ cytokine to combat GAS by isotype switching to IgG2c (which is opsonic for phagocytosis). Our data indicate the crucial role of IFN-ƴ in the protective immune response that, together with IgG2c, can induce protection against GAS.

Keywords: Group A streptococcus, IgG2c, IFN-γ, protection

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Authors: Carlos Riascos, Peter Thomson

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Real-time hybrid simulation (RTHS) is a modern cyber-physical technique used for the experimental evaluation of complex systems, that treats the system components with predictable behavior as a numerical substructure and the components that are difficult to model as an experimental substructure. Therefore it is an attractive method for evaluation of the response of civil structures under earthquake, wind and anthropic loads. Another practical application of RTHS is the evaluation of control systems, as these devices are often nonlinear and their characterization is an important step in the design of controllers with the desired performance. In this paper, the response of three-story shear frame controlled by a tuned liquid column damper (TLCD) and subject to base excitation is considered. Both passive and semi-active control strategies were implemented and are compared. While the passive TLCD achieved a reduction of 50% in the acceleration response of the main structure in comparison with the structure without control, the semi-active TLCD achieved a reduction of 70%, and was robust to variations in the dynamic properties of the main structure. In addition, a RTHS was implemented with the main structure modeled as a linear, time-invariant (LTI) system through a state space representation and the TLCD, with both control strategies, was evaluated on a shake table that reproduced the displacement of the virtual structure. Current assessment measures for RTHS were used to quantify the performance with parameters such as generalized amplitude, equivalent time delay between the target and measured displacement of the shake table, and energy error using the measured force, and prove that the RTHS described in this paper is an accurate method for the experimental evaluation of structural control systems.

Keywords: structural control, hybrid simulation, tuned liquid column damper, semi-active sontrol strategy

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Authors: Jyh-Cheng Chen, Tai-Jing Wang, Yun-Wei Lin

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Astaxanthin has been demonstrated to exhibit a wide range of beneficial effects including anti-inflammatory and anti-cancer properties. However, the molecular mechanism of astaxanthin-induced cytotoxicity in non-small cell lung cancer (NSCLC) cells has not been identified. Rad51 plays a central role in homologous recombination and high levels of Rad51 expression are observed in chemo- or radioresistant carcinomas. In this study, astaxanthin treatment inhibited cell viability and proliferation of two NSCLC cells, A549 and H1703. Treatment with astaxanthin decreased Rad51 expression and phospho-AKT protein level in a time and dose-dependent manner. Furthermore, expression of constitutively active AKT (AKT-CA) vector significantly rescued the decreased Rad51 protein and mRNA levels in astaxanthin-treated NSCLC cells. Combined treatment with PI3K inhibitors (LY294002 or wortmannin) and astaxanthin further decreased the Rad51 expression in NSCLC cells. Knockdown of Rad51 enhanced astaxanthin-induced cytotoxicity and growth inhibition in NSCLC cells. These findings may have implications for the rational design of future drug regimens incorporating astaxanthin for the treatment of NSCLC.

Keywords: astaxanthin, cytotoxicity, AKT, non-small cell lung cancer, PI3K

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Authors: Ines Raies, Eric Kohler, Marc Fleury, Béatrice Ledésert

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In this work, the impact of clay minerals on the formation damage of sandstone reservoirs is studied to provide a better understanding of the problem of deep geothermal reservoir permeability reduction due to fine particle dispersion and migration. In some situations, despite the presence of filters in the geothermal loop at the surface, particles smaller than the filter size (<1 µm) may surprisingly generate significant permeability reduction affecting in the long term the overall performance of the geothermal system. Our study is carried out on cores from a Triassic reservoir in the Paris Basin (Feigneux, 60 km Northeast of Paris). Our goal is to first identify the clays responsible for clogging, a mineralogical characterization of these natural samples was carried out by coupling X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray Spectroscopy (EDS). The results show that the studied stratigraphic interval contains mostly illite and chlorite particles. Moreover, the spatial arrangement of the clays in the rocks as well as the morphology and size of the particles, suggest that illite is more easily mobilized than chlorite by the flow in the pore network. Thus, based on these results, illite particles were prepared and used in core flooding in order to better understand the factors leading to the aggregation and deposition of this type of clay particles in geothermal reservoirs under various physicochemical and hydrodynamic conditions. First, the stability of illite suspensions under geothermal conditions has been investigated using different characterization techniques, including Dynamic Light Scattering (DLS) and Scanning Transmission Electron Microscopy (STEM). Various parameters such as the hydrodynamic radius (around 100 nm), the morphology and surface area of aggregates were measured. Then, core-flooding experiments were carried out using sand columns to mimic the permeability decline due to the injection of illite-containing fluids in sandstone reservoirs. In particular, the effects of ionic strength, temperature, particle concentration and flow rate of the injected fluid were investigated. When the ionic strength increases, a permeability decline of more than a factor of 2 could be observed for pore velocities representative of in-situ conditions. Further details of the retention of particles in the columns were obtained from Magnetic Resonance Imaging and X-ray Tomography techniques, showing that the particle deposition is nonuniform along the column. It is clearly shown that very fine particles as small as 100 nm can generate significant permeability reduction under specific conditions in high permeability porous media representative of the Triassic reservoirs of the Paris basin. These retention mechanisms are explained in the general framework of the DLVO theory

Keywords: geothermal energy, reinjection, clays, colloids, retention, porosity, permeability decline, clogging, characterization, XRD, SEM-EDS, STEM, DLS, NMR, core flooding experiments

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Authors: Muhammad Irfan, Guillermo Requena, Jan Haubrich

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Adhesively bonded aluminum joints are common in automotive and aircraft industries and are one of the enablers of lightweight construction to minimize the carbon emissions during transportation for a sustainable life. This study is focused on the effects of two thermal processing routes, i.e., by direct and induction heating, and their parameters on void formation in PA6 bonded aluminum EN-AW6082 joints. The joints were characterized microanalytically as well as by lap shear experiments. The aging resistance of the joints was studied by accelerated aging tests at 80°C hot water. It was found that the processing of single lap joints by direct heating in a convection oven causes the formation of a large number of voids in the bond line. The formation of voids in the convection oven was due to longer processing times and was independent of any surface pretreatments of the metal as well as the processing temperature. However, when processing at low temperatures, a large number of small-sized voids were observed under the optical microscope, and they were larger in size but reduced in numbers at higher temperatures. An induction heating process was developed, which not only successfully reduced or eliminated the voids in PA6 bonded joints but also reduced the processing times for joining significantly. Consistent with the trend in direct heating, longer processing times and higher temperatures in induction heating also led to an increased formation of voids in the bond line. Subsequent single lap shear tests revealed that the increasing void contents led to a 21% reduction in lap shear strengths (i.e., from ~47 MPa for induction heating to ~37 MPa for direct heating). Also, there was a 17% reduction in lap shear strengths when the consolidation temperature was raised from 220˚C to 300˚C during induction heating. However, below a certain threshold of void contents, there was no observable effect on the lap shear strengths as well as on hydrothermal aging resistance of the joints consolidated by the induction heating process.

Keywords: adhesive, aluminium, convection oven, induction heating, mechanical properties, nylon6 (PA6), pretreatment, void

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Authors: Heba Ahmed Nawafleh

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In this study, two commercial resins were evaluated to concentrate uranium from real solutions that were produced from analkaline leaching process of carbonate deposits. The adsorption was examined using a batch process. Different parameters were evaluated, including initial pH, contact time, temperature, adsorbent dose, and finally, uranium initial concentration. Both resins were effective and selective for uranium ions from the tested leaching solution. The adsorption isotherms data were well fitted for both resins using the Langmuir model. Thermodynamic functions (Gibbs free energy change ΔG, enthalpy change ΔH, and entropy change ΔS) were calculated for the adsorption of uranium. The result shows that the adsorption process is endothermic, spontaneous, and chemisorption processes took place for both resins. The kinetic studies showed that the equilibrium time for uranium ions is about two hours, where the maximum uptake levels were achieved. The kinetics studies were carried out for the adsorption of U ions, and the data was found to follow pseudo-second-order kinetics, which indicates that the adsorption of U ions was chemically controlled. In addition, the reusability (adsorption/ desorption) process was tested for both resins for five cycles, these adsorbents maintained removal efficiency close to first cycle efficiency of about 91% and 80%.

Keywords: uranium, adsorption, ion exchange, thermodynamic and kinetic studies

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Authors: Samih Ahmed, Guayente Minchot, Fritz King, Mikael Hallgren

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The stress ribbon system has numerous advantages that include but are not limited to increasing overall stiffness, control deflections, and reduction of materials consumption, which in turn, reduces the load and the cost. Nevertheless, its use is usually limited to bridges, in particular, pedestrian bridges; this can be attributed to the insufficient space that buildings' usually have for end supports, and/or back- stayed cables, that can accommodate the expected high pull-out forces occurring at the cables' ends. In this work, the roof of Västerås Travel Center, which will become one of the longest cable suspended roofs in the world, was chosen as a case study. The aim was to investigate the optimal technique to model the post-tensioned stress ribbon system for the roof structure using the FEM software SAP2000 and to assess any possible reduction in the pull-out forces, deflections, and concrete stresses. Subsequently, a conventional cable suspended roof was simulated using SAP2000, and compared to the post-tension stress ribbon system in order to examine the potential of the latter. Moreover, the effects of temperature loads and support movements on the final design loads were examined. Based on the study, a few practical recommendations concerning the construction method and the iterative design process, required to meet the architectural geometrical demands, are stated by the authors. The results showed that the post-tensioned stress ribbon system reduces the concrete stresses, overall deflections, and more importantly, reduces the pull-out forces and the vertical reactions at both ends by up to 16% and 11%, respectively, which substantially reduces the design forces for the support structures. The magnitude of these reductions was found to be highly correlated to the applied prestressing force, making the size of the prestressing force a key factor in the design.

Keywords: cable suspended, post-tension, roof structure, SAP2000, stress ribbon

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Authors: Marriette Sakah, Samuel Gyamfi, Morkporkpor Delight Sedzro, Christoph Kuhn

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Ghana is experiencing rapid economic development and its cities command an increasingly dominant role as centers of both production and consumption. Cities run on energy and are extremely vulnerable to energy scarcity, energy price escalations and health impacts of very poor air quality. The overriding concern in Ghana and other West African states is bridging the gap between energy demand and supply. Energy efficiency presents a cost-effective solution for supply challenges by enabling more coverage with current power supply levels and reducing the need for investment in additional generation capacity and grid infrastructure. In Ghana, major issues for energy policy formulation in residential applications include lack of disaggregated electrical energy consumption data and lack of thorough understanding with regards to socio-economic influences on energy efficiency investment. This study uses a bottom up approach to estimate baseline electricity end-use as well as the energy consumption of best available technologies to enable estimation of energy-efficiency resource in terms of relative reduction in total energy use for Tema city, Ghana. A ground survey was conducted to assess the probable consumer behavior in response to energy efficiency initiatives to enable estimation of the amount of savings that would occur in response to specific policy interventions with regards to funding and incentives provision targeted at households. Results show that 16% - 54% reduction in annual electricity consumption is reasonably achievable depending on the level of incentives provision. The saved energy could supply 10000 - 34000 additional households if the added households use only best available technology. Political support and consumer awareness are necessary to translate energy efficiency resources into real energy savings.

Keywords: achievable energy savings, energy efficiency, Ghana, household appliances

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Authors: S. Korkut, M. S. Kilic, E. Erhan

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In order to detect and quantify the phenolic contents of a wastewater with biosensors, two working electrodes based on modified Poly (Pyrrole) films were fabricated. Enzyme horseradish peroxidase was used as biomolecule of the prepared electrodes. Various phenolics were tested at the biosensor. Phenol detection was realized by electrochemical reduction of quinones produced by enzymatic activity. Analytical parameters were calculated and the results were compared with each other.

Keywords: carbon nanotube, phenol biosensor, polypyrrole, poly (glutaraldehyde)

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Authors: Yeganeh Attari, Gudmund Reidar Eiksund, Hans Peter Jostad

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In Geotechnical practice, there is no standard method recognized by the industry to account for the reduction of safety factor of a slope as an effect of soil displacement and pore pressure build-up during pile installation. Pile driving disturbs causes large strains and generates excess pore pressures in a zone that can extend many diameters from the installed pile, resulting in a decrease of the shear strength of the surrounding soil. This phenomenon may cause slope failure. Moreover, dissipation of excess pore pressure set-up may cause weakening of areas outside the volume of soil remoulded during installation. Because of complex interactions between changes in mean stress and shearing, it is challenging to predict installation induced pore pressure response. Furthermore, it is a complex task to follow the rate and path of pore pressure dissipation in order to analyze slope stability. In cohesive soils it is necessary to implement soil models that account for strain softening in the analysis. In the literature, several cases of slope failure due to pile driving activities have been reported, for instance, a landslide in Gothenburg that resulted in a slope failure destroying more than thirty houses and Rigaud landslide in Quebec which resulted in loss of life. Up to now, several methods have been suggested to predict the effect of pile driving on total and effective stress, pore pressure changes and their effect on soil strength. However, this is still not well understood or agreed upon. In Norway, general approaches applied by geotechnical engineers for this problem are based on old empirical methods with little accurate theoretical background. While the limitations of such methods are discussed, this paper attempts to capture the reduction in the factor of safety of a slope during pile driving, using coupled Finite Element analysis and cavity expansion method. This is demonstrated by analyzing a case of slope failure due to pile driving in Norway.

Keywords: cavity expansion method, excess pore pressure, pile driving, slope failure

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Authors: Lijun Wang, Zhen-Yu Chen

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A high-fat diet induces the accumulation of lipid hydroperoxides, accelerates the ageing process and causes a greater mortality in Drosophila melanogaster. The purple sweet potato is rich in antioxidant anthocyanin. The present study was to examine if supplementation of purple sweet potato anthocyanin (PSPA) could reduce the mortality of fruit flies fed a high-fat diet. Results showed that the mean lifespan of fruit fly was shortened from 56 to 35 days in a dose-dependent manner when lard in the diet increased from 0% to 20%. PSPA supplementation attenuated partially the lard-induced mortality. The maximum lifespan and 50% survival time were 49 and 27 days for the 10% lard control flies, in contrast, they increased to 57 and 30 days in the PSPA-supplemented fruit flies. PSPA-supplemented diet significantly up-regulated the mRNA of superoxide dismutase, catalase and Rpn11, compared with those in the control lard diet. In addition, PSPA supplementation could restore the climbing ability of fruit flies fed a 10% lard diet. It was concluded that the lifespan-prolonging activity of PSPA was most likely mediated by modulating the genes of SOD, CAT and Rpn11.

Keywords: purple sweet potato, anthocyanin, high-fat diet, oxidative stress

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Authors: Sruthi Ramagiri, Rajeev T.

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Free radical damage has been entailed as the major culprit in the ischemic stroke contributing for oxidative damage. Recent investigations on Hydroxy Safflower Yellow A (HSYA) suggested its role in cerebral ischemia and various neurodegenerative disorders with unidentified molecular mechanisms. The current study was designed to investigate putative therapeutic role and possible molecular mechanisms of HSYA administration during the onset of reperfusion in cerebral ischemia-reperfusion (I/R) injury in cerebral stroke. Cerebral stroke was achieved by focal ischemic model. HSYA (10 mg/kg) was injected intravenously via the tail vein 5 minutes before reperfusion. Losses of sensorimotor abilities were evaluated by neurological scoring, spontaneous locomotor activity, and rotarod performance. Extent of oxidative stress was evaluated by biochemical parameters i.e., malondialdehyde (MDA), Glutathione (GSH), Super Oxide Dismutase (SOD) and catalase levels. The infarct volume of brain was assessed by 2,3,5-triphenyl tetrazolium chloride (TTC) staining technique. Increased cerebral injury (I/R) was evidenced by motor impairment, increased infarct volume and elevation of MDA levels along with significant reduction in antioxidant i.e.,MDA levels along with significant reduction in antioxidant i.e., GSH, SOD and catalase levels when compared to sham control. However, post conditioning with HSYA (10 mg/kg, i.v.) at the onset of reperfusion has significantly ameliorated sensorimotor abilities, attenuated MDA levels and reduced the infarct volume as compared with vehicle treated I/R injury group. Moreover, HSYA treatments improved antioxidant enzyme levels as compared with vehicle treated I/R-injury group. In conclusion, it may be suggested that HSYA post conditioning could be novel therapeutic approach against I/R injury in cerebral stroke possibly through its anti-oxidant mechanism.

Keywords: HSYA, Ischemia reperfusion injury, oxidative stress, stroke

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Authors: Kingsley Izuagbe Ikeke, Abayomi O. Adetuyi

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The study investigated the removal efficiency of crystal violet from aqueous solution using chitosan-charcoal composite as adsorbent. Deproteination was carried out by placing 200g of powdered snail shell in 4% w/v NaOH for 2hours. The sample was then placed in 1% HCl for 24 hours to remove CaCO3. Deacetylation was done by boiling in 50% NaOH for 2hours. 10% Oxalic acid was used to dissolve the chitosan before mixing with charcoal at 55°C to form the composite. The composite was characterized by Fourier Transform Infra-Red and Scanning Electron Microscopy measurements. The efficiency of adsorption was evaluated by varying pH of the solution, contact time, initial concentration and adsorbent dose. Maximum removal of crystal violet by composite and activated charcoal was attained at pH10 while maximum removal of crystal violet by chitosan was achieved at pH 8. The results showed that adsorption of both dyes followed the pseudo-second-order rate equation and fit the Langmuir and Freundlich isotherms. The data showed that composite was best suited for crystal violet removal and also did relatively well in the removal of alizarin red. Thermodynamic parameters such as enthalpy change (ΔHº), free energy change (ΔGº) and entropy change (ΔSº) indicate that adsorption process of Crystal Violet was endothermic, spontaneous and feasible respectively.

Keywords: crystal violet, chitosan−charcoal composite, extraction process, sorption

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Authors: Mohamed Yusuf

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Aim: The growth promoting the effect of the blue-green filamentous alga Spirulina platensis (SP) was observed on meat type Japanese quail with antibiotic growth promoter alternative and immune enhancing power. Materials and Methods: This study was conducted on 180 Japanese quail chicks for 4 weeks to find out the effect of diet type (vegetarian protein diet [VPD] and fish meal protein diet [FMPD])- Spirulina dose interaction (1 or 2 g/kg diet) on growth performance, gut microbiota, and sensory meat quality of growing Japanese quails (1-5 weeks old). Results: Data revealed improvement (p<0.05) of weight gain, feed conversion ratio, and European efficiency index due to 1, 2 g (SP)/kg VPD, and 2 g (SP)/kg FMPD, respectively. There was a significant decrease of ileum mean pH value by 1 g(SP)/kg VPD. Concerning gut microbiota, there was a trend toward an increase in Lactobacilli count in both 1; 2 g (SP)/kgVPD and 2 g (SP)/kg FMPD. It was concluded that 1 or 2 g (SP)/kg vegetarian diet may enhance parameters of performance without obvious effect on both meat quality and gut microbiota. Moreover, 1 and/or 2 g (SP) may not be invited to share fishmeal based diet for growing Japanese quails. Conclusion: Using of SP will support the profitable production of Japanese quails fed vegetable protein diet.

Keywords: isocaloric, isonitrogenous, meat quality, performances, quails, spirulina, spirulina

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Authors: Peter Ekene Egwu

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Waste management is of critical importance in Africa for reasons related to public health, human dignity, climate resilience and environmental preservation. However, delivering waste management services requires adequate funding, which has generally been lacking in a context where the generation of waste is outpacing the development of waste management infrastructure in most cities. The sector represents a growing percentage of cities’ greenhouse gas (GHG) emissions, and some of the African cities profiled in this study are now designing waste management strategies with emission reduction in mind.

Keywords: management waste material, Africa, uses of new technology to manage waste, waste management

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Authors: Muntanavadee Maytapattana

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This research aims to study the effects of the Parent Training Program for Obesity Reduction (PTPOR) on child waist circumference and health behaviors of pre-school children at the Samut-Songkhram kindergarten school, Samut-Songkhram province, Thailand. The objective of this research is to evaluate the effectiveness of the PTPOR on child waist circumference and health behaviors of the pre-school children. The conceptual framework of this study is developed on the basis of the Ecological Systems Theory (EST), not only do the individual factors such as child characteristics and child risk factors contribute to the child’s weight status, but also other factors such as parenting style and family characteristics, as well as community and demographic factors. This research is a quasi-experimental study. Participants were pre-school overweight and obese children and their parents. Forty-one parent-child dyads were recruited into the program. Parents participated in two sessions including an educational session and a group discussion session. Research methodology uses Paired-Samples t-test to determine the difference between groups in the mean scores of the outcome variables of the children and parents. The research results show that there was significant difference between child waist circumferences mean score at the baseline and finishing the program at the 0.01 level (p = 0.001), mean score of the child waist circumference was decrease after finishing the program. And there was no significant difference between child exercise health behaviors mean score at the baseline and finishing the program at the 0.05 level; however, mean score of the child exercise behavior was increase after finishing the program. Meanwhile, there was significant difference between child dietary health behavior mean score at the baseline and finishing the program at the 0.01 level (p = 0.001), mean score of the child dietary was increase after finishing the program.

Keywords: PTPOR, child waist circumference, child health behaviors, pre-school children

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Authors: M. H. Rajikin, S. M. M. Syairah, A. R. Sharaniza

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Effects of nicotine on pre-partum body weight and preimplantation embryonic development has been reported previously. Present study was conducted to determine the effects of annatto (Bixa orellana)-derived delta-tocotrienol (TCT) (with presence of 10% gamma-TCT isomer) on the nicotine-induced reduction in body weight and 8-cell embryonic growth in mice. Twenty four 6-8 weeks old (23-25g) female balb/c mice were randomly divided into four groups (G1-G4; n=6). Those groups were subjected to the following treatments for 7 consecutive days: G1 (control) were gavaged with 0.1 ml tocopherol stripped corn oil, G2 was subcutaneously (s.c.) injected with 3 mg/kg/day of nicotine, G3 received concurrent treatment of nicotine (3 mg/kg/day) and 60 mg/kg/day of δ-TCT mixture (contains 90% delta & 10% gamma isomers) and G4 was given 60 mg/kg/day of δ-TCT mixture alone. Body weights were recorded daily during the treatment. On Day 8, females were superovulated with 5 IU Pregnant Mare’s Serum Gonadotropin (PMSG) for 48 hours followed with 5 IU human Chorionic Gonadotropin (hCG) before mated with males at the ratio of 1:1. Females were sacrificed by cervical dislocation for embryo collection 48 hours post-coitum. Collected embryos were cultured in vitro. Results showed that throughout Day 1 to Day 7, the body weight of nicotine treated group (G2) was significantly lower (p<0.05) than that of G1, G3 and G4. Intervention with δ-TCT mixture (G3) managed to increase the body weight close to the control group. This is also observed in the group treated with δ-TCT mixture alone (G4). The development of 8-cell embryos following in vitro culture (IVC) was totally inhibited in G2. Intervention with δ-TCT mixture (G3) resulted in the production of 8-cell embryos, although it was not up to that of the control group. Treatment with δ-TCT mixture alone (G4) caused significant increase in the average number of produced 8-cell embryo compared to G1. Present data indicated that δ-TCT mixture was able to reverse the body weight loss in nicotine treated mice and the development of 8-cell embryos was also improved.

Keywords: δ-tocotrienol, body weight, nicotine, preimplantation embryonic development

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Authors: Kayla Murray, Andrew Green, Gopi Paliyath, Keith Warriner

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Introduction: It is now acknowledged that control of human pathogens associated with fresh produce requires an integrated approach of several interventions as opposed to relying on post-harvest washes to remove field acquired contamination. To this end, current research is directed towards identifying such interventions that can be applied at different points in leafy green processing. Purpose: In the following the efficacy of different gas phase treatments to decontaminate whole lettuce heads during pre-processing storage were evaluated. Methods: Whole Cos lettuce heads were spot inoculated with L. monocytogenes, E. coli O157:H7 or Salmonella spp. The inoculated lettuce heads were then placed in a treatment chamber and exposed to ozone, chlorine dioxide or hydroxyl radicals at different time periods under a range of relative humidity. Survivors of the treatments were enumerated along with sensory analysis performed on the treated lettuce. Results: Ozone gas reduced L. monocytogenes by 2-log10 after ten-minutes of exposure with Salmonella and E. coli O157:H7 being decreased by 0.66 and 0.56-log cfu respectively. Chlorine dioxide gas treatment reduced L. monocytogenes and Salmonella on lettuce heads by 4 log cfu but only supported a 0.8 log cfu reduction in E. coli O157:H7 numbers. In comparison, hydroxyl radicals supported a 2.9 – 4.8 log cfu reduction of model human pathogens inoculated onto lettuce heads but required extended exposure times and relative humidity < 0.8. Significance: From the gas phase sanitizers tested, chlorine dioxide and hydroxyl radicals are the most effective. The latter process holds most promise based on the ease of delivery, worker safety and preservation of lettuce sensory characteristics. Although expose times for hydroxyl radicles was relatively long (24h) this should not be considered a limitation given the intervention is applied in store rooms or in transport containers during transit.

Keywords: gas phase sanitizers, iceberg lettuce heads, leafy green processing

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Authors: R. Gwynn, P. Panwalkar, K. Veravalli , M. Tofighi, R. Clement, A. Mofidi

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The aim of this study was to access the impact of Covid-19 and lockdown on the incidence, injury pattern, and treatment of tibial plateau fractures in a combined rural and urban population in wales. Methods: Retrospective study was performed to identify tibial plateau fractures in 15-month period of Covid-19 lockdown 15-month period immediately before lockdown. Patient demographics, injury mechanism, injury severity (based on Schatzker classification), and associated injuries, treatment methods, and outcome of fractures in the Covid-19 period was studied. Results: The incidence oftibial plateau fracture was 9 per 100000 during Covid-19, and 8.5 per 100000, and both were similar to previous studies. The average age was 52, and female to male ratio was 1:1 in both control and study group. High energy injury was seen in only 20% of the patients and 35% in the control groups (2=12, p<0025). 14% of the covid-19 population sustained other injuries as opposed 16% in the control group(2=0.09, p>0.95). Lower severity isolated lateral condyle fracturesinjury (Schatzker 1-3) were seen in 40% of fractures this was 60% in the control populations. Higher bicondylar and shaft fractures (Schatzker 5-6) were seen in 60% of the Covid-19 group and 35% in the control groups(2=7.8, p<0.02). Treatment mode was not impacted by Covid-19. The complication rate was low in spite of higher number of complex fractures and the impact of covid-19 pandemic. Conclusion: The associated injuries were similar in spite of a significantly lower mechanism of injury. There were unexpectedly worst tibial plateau fracture based Schatzker classification in the Covid-19 period as compared to the control groups. This was especially relevant for medial condyle and shaft fractures. This was postulated to be caused by reduction in bone density caused by lack of vitamin D and reduction in activity. The treatment mode and outcome was not impacted by the impact of Covid-19 on care for tibial plateau fractures.

Keywords: Covid-19, knee, tibial plateau fracture, trauma

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Authors: Imran Khan Pathan, Anil Bhandari, Peeyush K. Sharma, Rakesh K. Patel, Suresh Purohit

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Floating tablets of Marichyadi Vati were developed with an aim to prolong its gastric residence time and increase the bioavailability of drug. Rapid gastrointestinal transit could result in incomplete drug release from the drug delivery system above the absorption zone leading to diminished efficacy of the administered dose. The tablets were prepared by wet granulation technique, using HPMC E50 LV act as Matrixing agent, Carbopol as floating enhancer, microcrystalline cellulose as binder, sodium bi carbonate as effervescent agent with other excipients. The simplex lattice design was used for selection of variables for tablets formulation. Formulation was optimized on the basis of floating time and in vitro drug release. The results showed that the floating lag time for optimized formulation was found to be 61 second with about 97.32 % of total drug release within 3 hours. The in vitro release profiles of drug from the formulation could be best expressed zero order with highest linearity r2 = 0.9943. It was concluded that the gastroretentive drug delivery system can be developed for Marichyadi Vati containing piperine to increase the residence time of the drug in the stomach and thereby increasing bioavailability.

Keywords: piperine, Marichyadi Vati, gastroretentive drug delivery, floating tablet

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Authors: Beena Sethi

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This work involves the degradation of plastic waste in the presence of three different nanocatalysts. A thin film of LLDPE was formed with all three nanocatalysts separately in the solvent. Thermo Gravimetric Analysis (TGA) and Differential Scanning Calorimetric (DSC) analysis of polymers suggest that the presence of these catalysts lowers the degradation temperature and the change mechanism of degradation. Gas chromatographic analysis was carried out for two films. In gas chromatography (GC) analysis, it was found that degradation of pure polymer produces only 32% C3/C4 hydrocarbons and 67.6% C5/C9 hydrocarbons. In the presence of these catalysts, more than 80% of polymer by weight was converted into either liquid or gaseous hydrocarbons. Change in the mechanism of degradation of polymer was observed therefore more C3/C4 hydrocarbons along with valuable feedstock are produced. Adjustment of dose of nanocatalyst, use of nano-admixtures and recycling of catalyst can make this catalytic feedstock recycling method a good tool to get sustainable environment. The obtained products can be utilized as fuel or can be transformed into other useful products. In accordance with the principles of sustainable development, chemical recycling i.e. tertiary recycling of polymers along with the reuse (zero order recycling) of plastics can be the most appropriate and promising method in this direction. The tertiary recycling is attracting much attention from the viewpoint of the energy resource.

Keywords: degradation, differential scanning calorimetry, feedstock recycling, gas chromatography, thermogravimetric analysis

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Authors: Romel Cordova Shedan

Abstract:

The traditional seismic design is the methodology of Forced Based Design (FBD). The Displacement Based Design (DBD) is a seismic design that considers structural damage to achieve a failure mechanism of the structure before the collapse. It is easier to quantify damage of a structure with displacements rather than forces. Therefore, a structure to achieve an inelastic displacement design with good ductility, it is necessary to be damaged. The first part of this investigation is about differences between the methodologies of DBD and FBD with some DBD advantages. In the second part, there is a study case about a dual building 5-story, which is regular in plan and elevation. The building is located in a seismic zone, which acceleration in firm soil is 45% of the acceleration of gravity. Then it is applied both methodologies into the study case to compare its displacements, shear forces and overturning moments. In the third part, the Dynamic Time History Analysis (DTHA) is done, to compare displacements with DBD and FBD methodologies. Three accelerograms were used and the magnitude of the acceleration scaled to be spectrum compatible with design spectrum. Then, using ASCE 41-13 guidelines, the hinge plastics were assigned to structure. Finally, both methodologies results about study case are compared. It is important to take into account that the seismic performance level of the building for DBD is greater than FBD method. This is due to drifts of DBD are in the order of 2.0% and 2.5% comparing with FBD drifts of 0.7%. Therefore, displacements of DBD is greater than the FBD method. Shear forces of DBD result greater than FBD methodology. These strengths of DBD method ensures that structure achieves design inelastic displacements, because those strengths were obtained due to a displacement spectrum reduction factor which depends on damping and ductility of the dual system. Also, the displacements for the study case for DBD results to be greater than FBD and DTHA. In that way, it proves that the seismic performance level of the building for DBD is greater than FBD method. Due to drifts of DBD which are in the order of 2.0% and 2.5% compared with little FBD drifts of 0.7%.

Keywords: displacement-based design, displacement spectrum reduction factor, dynamic time history analysis, forced based design

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Authors: Maria Kralova, Michal Palecek

Abstract:

We have detected factors leading to recidivism (the Czech Republic data). The employment during imprisonment turned out to be the most significant predictor with a positive effect on reduction of a rate of recidivism. Accordingly, we mainly focus on this predictor and its economic consequences. Smart public policy can cut government costs dramatically as more than a half of prisoners in the Czech Republic are recidivists. The operating cost cut of the Czech prison service could be CZK 127,680,000 (USD 5,889,623) in 2013 if a public policy had been set smarter.

Keywords: cost-cut, effective, optimal, public policy, reducing recidivism

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Authors: Bikram K. Das, Kalyan K. Chattopadhyay

Abstract:

The advent of 2-D materials in the last decade has induced a fresh spur of growth in fuel cell technology as these materials have some highly promising traits that can be exploited to felicitate Oxygen Reduction Reaction (ORR) in an efficient way. Among the various 2-D carbon materials, graphyne (Gy) and graphdiyne (Gdy)1 with their intrinsic non-uniform charge distribution holds promises in this purpose and it is expected2 that substitutional Nitrogen (N) doping could further enhance their efficiency. In this regard, dispersive force corrected density functional theory is used to map the oxygen reduction reaction (ORR) kinetics of five different kinds of N doped graphyne and graphdiyne systems (namely αGy, βGy, γGy, RGy and 6,6,12Gy and Gdy) in alkaline medium. The best doping site for each of the Gy/ Gdy system is determined comparing the formation energies of the possible doping configurations. Similarly, the best di-oxygen (O₂) adsorption sites for the doped systems are identified by comparing the adsorption energies. O₂ adsorption on all N doped Gy/ Gdy systems is found to be energetically favorable. ORR on a catalyst surface may occur either via the Eley-Rideal (ER) or the Langmuir–Hinschelwood (LH) pathway. Systematic studies performed on the considered systems reveal that all of them favor the ER pathway. Further, depending on the nature of di-oxygen adsorption ORR can follow either associative or dissociative mechanism; the possibility of occurrence of both the mechanisms is tested thoroughly for each N doped Gy/ Gdy. For the ORR process, all the Gy/Gdy systems are observed to prefer the efficient four-electron pathway but the expected monotonically exothermic reaction pathway is found only for N doped 6,6,12Gy and RGy following the associative pathway and for N doped βGy, γGy and Gdy following the dissociative pathway. Further computation performed for these systems reveals that for N doped 6,6,12Gy, RGy, βGy, γGy and Gdy the overpotentials are 1.08 V, 0.94 V, 1.17 V, 1.21 V and 1.04 V respectively depicting N doped RGy is the most promising material, to carry out ORR in alkaline medium, among the considered ones. The stability of the ORR intermediate states with the variation of pH and electrode potentials is further explored with Pourbiax diagrams and the activities of these systems in the alkaline medium are compared with the prior reported B/N doped identical systems for ORR in an acidic medium in terms of a common descriptor.

Keywords: graphdiyne, graphyne, nitrogen-doped, ORR

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Authors: Raja Chinnappan, Huda Alanazi, Shanmugam Easwaramoorthi, Tanveer Mir, Balamurugan Kanagasabai, Ahmed Yaqinuddin, Sandhanasamy Devanesan, Mohamad S. AlSalhi

Abstract:

Serum albumin (SA) is a highly rich water-soluble protein in plasma. It is known to maintain the living organisms' health and help to maintain the proper liver function, kidney function, and plasma osmolality in the body. Low levels of serum albumin are an indication of liver failure and chronic hepatitis. Therefore, it is important to have a low-cost, accurate and rapid method. In this study, we designed a fluorescent probe, triphenylamine rhodanine-3-acetic acid (mRA), which triggers the fluorescence signal upon binding with serum albumin (SA). mRA is a bifunctional molecule with twisted intramolecular charge transfer (TICT)-induced emission characteristics. An aqueous solution of mRA has an insignificant fluorescence signal; however, when mRA binds to SA, it undergoes TICT and turns on the fluorescence emission. A SA dose-dependent fluorescence signal was performed, and the limit of detection was found to be less than ng/mL. The specific binding of SA was tested from the cross-reactivity study using similar structural or functional proteins.

Keywords: serum albumin, fluorescent sensing probe, liver diseases, twisted intramolecular charge transfer

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Authors: Meriem El Kolli, Hocine Laouer, Hayet El Kolli, Salah Akkal

Abstract:

The methanolic extract (ME) of C. montanum obtained by a hydo-alcoholic maceration and its polyphenol content was evaluated by Folin-Ciocalteu method. This extract and C. montanum essential oil were screened for antimicrobial activity against 21 microbial strains by agar diffusion method. MICs of the EO were determined by the broth micro dilution method. The mechanism of action of the EO was determined on the susceptible strains by the time kill assay and the lysis experience. Antioxidant properties were studied by both free DPPH radical scavenging and reducing power techniques. The TPC in the ME showed a high level of 101.50 ± 5.33 mg GAE /mg. B. cereus was the most sensitive strain with MIC of 55.5 µg/ml , then K. pneumoniae (111 µg/ml). A remarkable decrease in a survival rate as well as in the absorbance at 260 nm were recorded, which suggest that the cytoplasm membrane is one of the targets of the EO. Antioxidant effects were concentration dependent and IC50 values were 1.09 ± 0.37 µg/ml for the EO and 65.04 ± 0.00 µg/ml for the ME by DPPH method and a reducing power dose-dependent. In conclusion, C. montanum extracts showed potent which could be exploited in the food industry for food preservation.

Keywords: C. montanum, Apiaceae, essential oils, antimicrobial activity, antioxidant activity, reducing power

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Authors: Jeremy Moloney

Abstract:

A major oil and gas operator in western Canada producing approximately 50,000 BOE per day of sour fluids was experiencing increased water production along with decreased oil production over several years. The higher water volumes being produced meant an increase in the operator’s incumbent corrosion inhibitor (CI) chemical requirements but with reduced oil production revenues. Thus, a cost-effective corrosion inhibitor solution was sought to deliver enhanced corrosion mitigation of the carbon steel pipeline infrastructure but at reduced chemical injection dose rates. This paper presents the laboratory work conducted on the development of a corrosion inhibitor under the operator’s simulated sour operating conditions and then subsequent field testing of the product. The new CI not only provided extremely good levels of general and localized corrosion inhibition and outperformed the incumbent CI under the laboratory test conditions but did so at vastly lower concentrations. In turn, the novel CI product facilitated field chemical injection rates to be optimized and reduced by 40% compared with the incumbent whilst maintaining superior corrosion protection resulting in significant cost savings and associated sustainability benefits for the operator.

Keywords: carbon steel, sour gas, hydrogen sulphide, localized corrosion, pitting, corrosion inhibitor

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Authors: Sachin Kamble, Raghothama Anekal, Shivakumar Bhavi

Abstract:

Thermal management of electronic components packaged inside an IP65 rated enclosure is of prime importance in industrial applications. Electrical enclosure protects the multiple board configurations such as inverter, power, controller board components, busbars, and various power dissipating components from harsh environments. Industrial environments often experience relatively warm ambient conditions, and the electronic components housed in the enclosure dissipate heat, due to which the enclosures and the components require thermal management as well as reduction of internal ambient temperatures. Design of Experiments based thermal simulation approach with MOSFET arrangement, Heat sink design, Enclosure Volume, Copper and Aluminum Spreader, Power density, and Printed Circuit Board (PCB) type were considered to optimize air temperature inside the IP65 enclosure to ensure conducive operating temperature for controller board and electronic components through the different modes of heat transfer viz. conduction, natural convection and radiation using Ansys ICEPAK. MOSFET’s with the parallel arrangement, IP65 enclosure molded heat sink with rectangular fins on both enclosures, specific enclosure volume to satisfy the power density, Copper spreader to conduct heat to the enclosure, optimized power density value and selecting Aluminum clad PCB which improves the heat transfer were the contributors towards achieving a conducive operating temperature inside the IP-65 rated Motor Inverter enclosure. A reduction of 52 ℃ was achieved in internal ambient temperature inside the IP65 enclosure between baseline and final design parameters, which met the operative temperature requirements of the electronic components inside the IP-65 rated Motor Inverter.

Keywords: Ansys ICEPAK, aluminium clad PCB, IP 65 enclosure, motor inverter, thermal simulation

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Authors: Arben Murtezani, Shefqet Mrasori, Vančo Spirov, Bukurije Rama, Oliver Dimitrovski, Visar Bunjaku

Abstract:

Overview: Temporomandibular disorders (TMDs) are chronic musculoskeletal pain conditions. Clinical indicators of discomfort are related to the use of the joint stiffness during first motions after extended rest and restricted joint range of motion can cause substantial pain and disability. There is little evidence that physical therapy methods of management cause long-lasting reduction in signs and symptoms. Exercise programs premeditated to improve physical fitness have beneficial effects on chronic pain and disability of the musculoskeletal system. Objective: The aim of this study was to assess the effectiveness of physical therapy interventions in the management of temporomandibular disorders. Materials and Methods: A prospective comparative study with a 2-month follow-up period was conducted between April 2016 and June 2016 at the Physical Medicine and Rehabilitation Clinic in Prishtina. Forty six patients with TMDs, (more than three months duration of symptoms) were randomized into two groups: the TENS therapy group (n=24) and combination of active exercise and manual therapy group (n=22). The TENS therapy group patients were treated with twelve sessions of TENS. The treatment period of both groups was 3 weeks at an outpatient clinic. Following main outcome measures were evaluated: (1) pain at rest (2) pain at stress (3) impairment (4) mouth opening at base-line, before and after treatment and at 3 month follow-up. Results: Significant reduction in pain was observed in both treatment groups. In the TENS group 73% (16/22) achieved at least 80% improvement from baseline in TMJ pain at 2 months compared with 54% (13/24) in the exercise group (difference of 19%; 95% confidence interval 220 to 30%). Active and passive maximum mouth opening has been greater in the TENS group (p < 0.05). Conclusion: Exercise therapy in combination with TENS seems to be useful in the treatment of temporomandibular disorders.

Keywords: temporomandibular joint disorders, TENS, manual therapy, exercise

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Authors: Ratnakar Rao, Subair Khan, Hari Haran

Abstract:

Posterior cruciate ligament (PCL) avulsion fractures is a rare condition and commonly mismanaged.Surgical reattachment has been shown to produce better result compared with conservative management.Only few techniques are reported in arthroscopic fixation of PCL Avulsion Fracture and they are complex.We describe a new technique in fixation of the PCL Avulsion fracture through a posterior trans septal portal using button fixation device (Mini Tight Rope). Eighteen patients with an isolated posterior cruciate ligament avulsion fracture were operated under arthroscopy. Standard Antero Medial Portal and Antero Lateral portals made and additional Postero Medial and Postero Lateral portals made and trans Septal portal established. Avulsion fracture identified, elevated, prepared. Reduction achieved using PCL Tibial guide (Arthrex) and fixation was achieved using Mini Tight Rope,Arthrex (2 buttons with a suture). Reduction confirmed using probe and Image intensifier. Postoperative assessment made clinically and radiologically. 15 patients had good to excellent results with no posterior sag or instability. The range of motion was normal. No complications were recorded per operatively. 2 patients had communition of the fragment while drilling, for one patient it was managed by suturing technique and the second patient PCL Reconstruction was done. One patient had persistent instability with poor outcome. Establishing trans septal portal helps in better visualization of the posterior compartment of the knee. Assessment of the bony fragment, preparation 0f the bone bed andit protects from injury to posterior neurovascular structures. Fixation using the button with suture (Mini Tight Rope) is stable and easily reproducible for PCL Avulsion fracture with single large fragment.

Keywords: PCL avulsion, arthroscopy, transeptal, minitight rope technique

Procedia PDF Downloads 258