Search results for: branched chain amino acid

Authors: Indranil Chakraborty, Kalyan Mandal

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Three new α-hydroxy carboxylate group functionalized MnFe₂O₄ nanoparticles (NPs) have been developed to explore the microscopic origin of ligand modified fluorescence and magnetic properties of nearly monodispersed MnFe₂O₄ NPs. The surface functionalization has been carried out with three small organic ligands (tartrate, malate, and citrate) having different number of α-hydroxy carboxylate functional group along with steric effect. Detailed study unveils that α-hydroxy carboxylate moiety of the ligands plays key role to generate intrinsic fluorescence in functionalized MnFe₂O₄ NPs through the activation of ligand to metal charge transfer transitions, associated with ligand-Mn²⁺/Fe³⁺ interactions along with d-d transition corresponding to d-orbital energy level splitting of Fe³⁺ ions on NP surface. Further, MnFe₂O₄ NPs show a maximum 140.88% increase in coercivity and 97.95% decrease in magnetization compared to its bare one upon functionalization. The ligands that induce smallest crystal field splitting of d-orbital energy level of transition metal ions are found to result in strongest ferromagnetic activation of the NPs. Finally, our developed tartrate functionalized MnFe₂O₄ (T-MnFe₂O₄) NPs have been utilized for studying DNA binding interaction and nuclease activity for stimulating their beneficial activities toward diverse biomedical applications. The spectroscopic measurements indicate that T-MnFe₂O₄ NPs bind calf thymus DNA by intercalative mode. The ability of T-MnFe₂O₄ NPs to induce DNA cleavage was studied by gel electrophoresis technique where the complex is found to promote the cleavage of pBR322 plasmid DNA from the super coiled form I to linear coiled form II and nicked coiled form III with good efficiency. This may be taken into account for designing new biomolecular detection agents and anti-cancer drug which can open up a new door toward diverse non-invasive biomedical applications.

Keywords: MnFe₂O₄ nanoparticle, α-hydroxy carboxylic acid, comparative fluorescence, magnetism study, DNA interaction, nuclease activity

Procedia PDF Downloads 139

Authors: Sungmin Park, Gyungmok Nam, Seungpyo Woo, Young Choi, Sangheon Park, Sang-Hee Yoon

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Puncturing human skin with microneedles is critically important for microneedle-mediate drug delivery. Despite of extensive efforts in the past decades, the scale-up fabrication of sharp-tipped and high-aspect-ratio microneedles, especially made of biodegradable polymers, is still a long way off. Here, we present a UV dose insensitive and cost-effective microfabrication method for the biodegradable polymer microneedles with sharp tips and long lengths which can pierce human skin with low insertion force. The biodegradable polymer microneedles are fabricated with the polymer solution casting where a poly(lactic-co-glycolic acid) (PLGA, 50:50) solution is coated onto a SU-8 mold prepared with a reverse, ramped, and rotational (R3) UV exposure. The R3 UV exposure is modified from the multidirectional UV exposure both to suppress UV reflection from the bottom surface without anti-reflection layers and to optimize solvent concentration in the SU-8 photoresist, therefore achieving robust (i.e., highly insensitive to UV dose) and cost-effective fabrication of biodegradable polymer microneedles. An optical model for describing the spatial distribution of UV irradiation dose of the R3 UV exposure is also developed to theoretically predict the microneedle geometry fabricated with the R3 UV exposure and also to demonstrate the insensitiveness of microneedle geometry to UV dose. In the experimental characterization, the microneedles fabricated with the R3 UV exposure are compared with those fabricated with a conventional method (i.e., multidirectional UV exposure). The R3 UV exposure-based microfabrication reduces the end-tip radius by a factor of 5.8 and the deviation from ideal aspect ratio by 74.8%, compared with conventional method-based microfabrication. The PLGA microneedles fabricated with the R3 UV exposure pierce full-thickness porcine skins successfully and are demonstrated to completely dissolve in PBS (phosphate-buffered saline). The findings of this study will lead to an explosive growth of the microneedle-mediated drug delivery market.

Keywords: R³ UV exposure, optical model, UV dose, reflection, solvent concentration, biodegradable polymer microneedle

Procedia PDF Downloads 166

Authors: Kyung Jin Kim, Jiwon Kwak, Jae-Hoon Lee, Soo Suk Lee

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MicroRNAs (miRNA) are a class of endogenous, single-stranded, small, and non-protein coding RNA molecules typically 20-25 nucleotides long. They are thought to regulate the expression of other genes in a broad range by binding to 3’- untranslated regions (3’-UTRs) of specific mRNAs. The detection of miRNAs is very important for understanding of the function of these molecules and in the diagnosis of variety of human diseases. However, detection of miRNAs is very challenging because of their short length and high sequence similarities within miRNA families. So, a simple-to-use, low-cost, and highly sensitive method for the detection of miRNAs is desirable. In this study, we demonstrate a novel bi-directional extension (BDE) assay. In the first step, a specific linear RT primer is hybridized to 6-10 base pairs from the 3’-end of a target miRNA molecule and then reverse transcribed to generate a cDNA strand. After reverse transcription, the cDNA was hybridized to the 3’-end which is BDE sequence; it played role as the PCR template. The PCR template was amplified in an SYBR green-based quantitative real-time PCR. To prove the concept, we used human brain total RNA. It could be detected quantitatively in the range of seven orders of magnitude with excellent linearity and reproducibility. To evaluate the performance of BDE assay, we contrasted sensitivity and specificity of the BDE assay against a commercially available poly (A) tailing method using miRNAs for let-7e extracted from A549 human epithelial lung cancer cells. The BDE assay displayed good performance compared with a poly (A) tailing method in terms of specificity and sensitivity; the CT values differed by 2.5 and the melting curve showed a sharper than poly (A) tailing methods. We have demonstrated an innovative, cost-effective BDE assay that allows improved sensitivity and specificity in detection of miRNAs. Dynamic range of the SYBR green-based RT-qPCR for miR-145 could be represented quantitatively over a range of 7 orders of magnitude from 0.1 pg to 1.0 μg of human brain total RNA. Finally, the BDE assay for detection of miRNA species such as let-7e shows good performance compared with a poly (A) tailing method in terms of specificity and sensitivity. Thus BDE proves a simple, low cost, and highly sensitive assay for various miRNAs and should provide significant contributions in research on miRNA biology and application of disease diagnostics with miRNAs as targets.

Keywords: bi-directional extension (BDE), microRNA (miRNA), poly (A) tailing assay, reverse transcription, RT-qPCR

Procedia PDF Downloads 166

Authors: Santi Maneewatchararangsri, Wanpen Chaicumpa, Patcharin Saengjaruk, Urai Chaisri

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Leptospirosis is a globally neglected disease that continues to be a significant public health and veterinary burden, with millions of cases reported each year. Early and accurate differential diagnosis of leptospirosis from other febrile illnesses and the development of a broad spectrum of leptospirosis vaccines are needed. The LipL32 outer membrane lipoprotein is a member of Leptospira adhesive matrices and has been found to exert hemolytic activity to erythrocytes in vitro. Therefore, LipL32 is regarded as a potential target for diagnosis, broad-spectrum leptospirosis vaccines, and for passive immunotherapy. In this study, we established LipL32-specific mouse monoclonal antibodies, mAbLPF1 and mAbLPF2, and their respective mouse- and humanized-engineered single chain variable fragment (ScFv). Their antibodies’ neutralizing activities against Leptospira-mediated hemolysis in vitro, and the therapeutic efficacy of mAbs against heterologous Leptospira infected hamsters were demonstrated. The epitope peptide of mAb LPF1 was mapped to a non-contiguous carboxy-terminal β-turn and amphipathic α-helix of LipL32 structure contributing to phospholipid/host cell adhesion and membrane insertion. We found that the mAbLPF2 epitope was located on the interacting loop of peptide binding groove of the LipL32 molecule responsible for interactions with host constituents. Epitope sequences are highly conserved among Leptospira spp. and are absent from the LipL32 superfamily of other microorganisms. Both epitopes are surface-exposed, readily accessible by mAbs, and immunogenic. However, they are less dominant when revealed by LipL32-specific immunoglobulins from leptospirosis-patient sera and rabbit hyperimmune serum raised by whole Leptospira. Our study also demonstrated an adhesion inhibitory activity of LipL32 protein to host membrane components and cells mediated by mAbs as well as an anti-hemolytic activity of the respective antibodies. The therapeutic antibodies, particularly the humanized-ScFv, have a potential for further development as non-drug therapeutic agent for human leptospirosis, especially in subjects allergic to antibiotics. The epitope peptides recognized by two therapeutic mAbs have potential use as tools for structure-function studies. Finally, protective peptides may be used as a target for epitope-based vaccines for control of leptospirosis.

Keywords: leptospira lipl32-specific antibodies, therapeutic epitopes, epitopes characterization, immunotherapy

Procedia PDF Downloads 297

Authors: Gabriela Rivadeneyra-Romero, Claudia del C. Gutierrez Torres, Sergio A. Martinez-Delgadillo, Victor X. Mendoza-Escamilla, Alejandro Alonzo-Garcia

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Ultrasonic degradation is currently being used in sonochemical reactors to degrade pollutant compounds from aqueous media, as emerging contaminants (e.g. pharmaceuticals, drugs and personal care products.) because they can produce possible ecological impacts on the environment. For this reason, it is important to develop appropriate water and wastewater treatments able to reduce pollution and increase reuse. Pollutants such as textile dyes, aromatic and phenolic compounds, cholorobenzene, bisphenol-A and carboxylic acid and other organic pollutants, can be removed from wastewaters by sonochemical oxidation. The effect on the removal of pollutants depends on the type of the ultrasonic frequency used; however, not much studies have been done related to the behavior of the fluid into the sonoreactors operated at different ultrasonic frequencies. Based on the above, it is necessary to study the hydrodynamic behavior of the liquid generated by the ultrasonic irradiation to design efficient sonoreactors to reduce treatment times and costs. In this work, it was studied the hydrodynamic behavior of the fluid in sonochemical reactors at different frequencies (250 kHz, 500 kHz and 1000 kHz). The performances of the sonoreactors at those frequencies were simulated using computational fluid dynamics (CFD). Due to there is great sound speed gradient between piezoelectric and fluid, k-e models were used. Piezoelectric was defined as a vibration surface, to evaluate the different frequencies effect on the fluid into sonochemical reactor. Structured hexahedral cells were used to mesh the computational liquid domain, and fine triangular cells were used to mesh the piezoelectric transducers. Unsteady state conditions were used in the solver. Estimation of the dissipation rate, flow field velocities, Reynolds stress and turbulent quantities were evaluated by CFD and 2D-PIV measurements. Test results show that there is no necessary correlation between an increase of the ultrasonic frequency and the pollutant degradation, moreover, the reactor geometry and power density are important factors that should be considered in the sonochemical reactor design.

Keywords: CFD, reactor, ultrasound, wastewater

Procedia PDF Downloads 190

Authors: T. Poppendieker

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A new innovative tool for self-myofascial release is widely and increasingly used among athletes of various sports. The application of the foam roll is suggested to improve muscle performance and flexibility. Attempts to examine acute and somewhat long term effects of either have been conducted over the past ten years. However, the results of muscle performance have been inconsistent. It is suggested that regular use over a long period of time results in a different, muscle performance improving outcome. This study examines long-term effects of regular foam rolling combined with a short plyometric routine vs. solely the same plyometric routine on muscle performance and flexibility over a period of six weeks. Results of counter movement jump (CMJ), squat jump (SJ), and isometric maximal force (IMF) of a 90° horizontal squat in a leg-press will serve as parameters for muscle performance. Data on the range of motion (ROM) of the sit and reach test will be used as a parameter for the flexibility assessment. Muscle activation will be measured throughout all tests. Twenty male and twenty female members of a Frankfurt area fitness center chain (7.11) with an average age of 25 years will be recruited. Women and men will be randomly assigned to a foam roll (FR) and a control group. All participants will practice their assigned routine three times a week over the period of six weeks. Tests on CMJ, SJ, IMF, and ROM will be taken before and after the intervention period. The statistic software program SPSS 22 will be used to analyze the data of CMJ, SJ, IMF, and ROM under consideration of muscle activation by a 2 x 2 x 2 (time of measurement x gender x group) analysis of variance with repeated measures and dependent t-test analysis of pre- and post-test. The alpha level for statistic significance will be set at p ≤ 0.05. It is hypothesized that a significant difference in outcome based on gender differences in all four tests will be observed. It is further hypothesized that both groups may show significant improvements in their performance in the CMJ and SJ after the six-week period. However, the FR group is hypothesized to achieve a higher improvement in the two jump tests. Moreover, the FR group may increase IMF as well as flexibility, whereas the control group may not show likewise progress. The results of this study are crucial for the understanding of long-term effects of regular foam roll application. The collected information on the matter may help to motivate the incorporation of foam rolling into training routines, in order to improve athletic performances.

Keywords: counter movement jump, foam rolling, isometric maximal force, long term effects, self-myofascial release, squat jump

Procedia PDF Downloads 286

Authors: Héctor González Espinosa, Ricardo Ivan Cordova Chávez, Alejandra Contreras Ramos, Itzia Irene Padilla Martínez, José Guadalupe Trujillo Ferrara, Marvin Antonio Soriano Ursúa

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Boronic acids are able to create diester bonds with carbohydrates because of their hydroxyl groups; in nature, there are some organoborates with these characteristics, such as the calcium fructoborate, formed by the union of two fructose molecules and a boron atom, synthesized by plants. In addition, it has been observed that, in animal cells only the compounds with cis-diol functional groups are capable of linking to boric or boronic acids. The formation of these organoboron compounds could impair the physical and chemical properties of the precursors, even their acute toxicity. In this project, two carbohydrate-derived boron-containing compounds from D-fructose and D-arabinose and phenylboronic acid are analyzed by different spectroscopy techniques such as Raman, Infrared with Fourier Transform Infrared (FT-IR), Nuclear Magnetic Resonance (NMR) and X-ray diffraction crystallography to describe their chemical characteristics. Also, an acute toxicity test was performed to determine their LD50 using the Lorke’s method. It was confirmed by multiple spectra the formation of the adducts by the generation of the diester bonds with a β-D-pyranose of fructose and arabinose. The most prominent findings were the presence of signals corresponding to the formation of new bonds, like the stretching of B-O bonds, or the absence of signals of functional groups like the hydroxyls presented in the reagents used for the synthesis of the adducts. The NMR spectra yielded information about the stereoselectivity in the synthesis reaction, observed by the interaction of the protons and their vicinal atoms in the anomeric and second position carbons; but also, the absence of a racemic mix by the finding of just one signal in the range for the anomeric carbon in the 13C NMR spectra of both adducts. The acute toxicity tests by the Lorke’s method showed that the LD50 value for both compounds is 1265 mg/kg. Those results let us to propose these adducts as highly safe agents for further biological evaluation with medical purposes.

Keywords: acute toxicity, adduct, boron, carbohydrate, diester bond

Procedia PDF Downloads 64

Authors: Nazmin Akter, Tariqul Islam, Abu Sayed

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Food loss and waste have become critical global issues, with approximately one-third of the world's food production being wasted. Among the various food products, horticultural fruits and vegetables are especially susceptible to loss due to their relatively short shelf lives. Litchi (Litchi chinensis) is one of Bangladesh's most important horticultural fruits. But the problem with this fruit is its short shelf life by losing weight faster after harvest. The experiment was carried out at Hajee Mohammad Danesh Science and Technology University, Dinajpur-5200 Bangladesh during 2020-2021. The objective of this experiment was to see the impact of nutrients viz., urea (1%), calcium chloride (1%), borax (1%), and their combinations on fruit quality and shelf life of litchi cv. Bombai. The experiment was laid out in a randomized block design with 7 treatments and 3 replications. Two sprays of each treatment were applied from the last week of May to June (at 20-day intervals). The results indicated that all the treatments significantly improved the quality parameters of litchi fruits as compared to the control. In terms of physicochemical characteristics fruit weight (20.30g), fruit volume (20m ml), and pulp percent (17.14) were found maximum with minimum stone percent (11.09) with the application of urea 1% + borax 1%+ calcium chloride 1%. Maximum TSS (19.62oBrix), TSS/acidity ratio (24.57), maximum ascorbic acid (45.19 mg/100 g pulp), and minimum acidity (0.80%) were reported with the application of T6 (Urea 1% + borax 1%+ calcium chloride 1%) treatments whereas fruits treated with urea 1% + borax 1% gave maximum total sugars (26.64%) and reducing sugars (19.19%) as compared to control. In the case of storage characters, application of Urea 1% + borax 1%+ calcium chloride 1% resulted in a minimum physiological loss in weight (6.11%), (8.41%), and (10.65%) for 2 days, 4 days, and 6 days respectively. In conclusion, to obtain better quality and increased storage period of litchi fruits, two sprays of urea, borax, and calcium chloride (1%) could be used during the fruit growth and development period at fortnightly intervals.

Keywords: litchi chinensis, preharvest, quality, shelf life, postharvest

Procedia PDF Downloads 71

Authors: Cherif Y., Ghariani R., Derbal S., Farhati S., Ben Dahmen F., Abdallah M.

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Introduction: Tuberculosis (TBC) is a frequent infection and is still a major public health problem in Tunisia. The aim of this work is to focus on diagnostic and therapeutic characteristics of TBC in patients referred to our internal medicine department. Patients and Methods: The study was retrospective and descriptive of a cohort of consecutive cases treated from January 2016 to December 2019, collecting patients with latent or patent TBC. Twenty-eight medical records of adults diagnosed with TBC were reviewed. Results: Twenty-eight patients, including 18 women and 10 men, were diagnosed with TBC. Their mean age is 48 years (range: 22-78 years). Five patients have a medical history of diabetes mellitus, 1 patient was followed for systemic lupus erythematosus treated with corticosteroids and immunosuppressant drugs, and another was treated with corticosteroids for Mac Duffy syndrome. The TBC is latent in 12 cases and patent in 16 cases. The most common symptoms were fever and weight loss and were found in 10 cases, a cough in 2 cases, sputum in 3 cases, lymph nodes in 4 cases, erythema nodosum in 2 cases, and neurological signs in 3 cases. Lymphopenia is noticed in 3 cases and a biological inflammatory syndrome in 18 of the cases. The purified protein derivate reaction was positive in 17 cases, anergic in 3 cases, negative in 5 cases, and not done in 3 cases. The acid-fast bacilli stain culture was strongly positive in one patient. The histopathological study was conclusive in 11 patients and showed granulomatosis with caseous necrosis. TBC was pulmonary in 7 patients, lymph node in 7 cases, peritoneal in 7 cases, digestive in 1 case, neuromeningeal in 3 cases, and thyroïd in 1 case. Seven patients had multifocal TBC. All the patients received anti-tuberculosis treatment with a mean duration of 8 months with no failure or relapse with an average follow-up time of 10.58 months. Conclusion: Diagnosis and management of TBC remain essential to avoid serious complications. The survey is necessary to ensure timely detection and treatment of infected adults to decrease its incidence. The best treatment remains preventive through vaccination and improving social and economic conditions.

Keywords: tuberculosis, infection, autoimmune disease, granulomatosis

Procedia PDF Downloads 185

Authors: Abul Hashem

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The experiment was conducted to find out the effect of different levels of Moringa oleifiera leaf extract and synthetic antioxidant (Beta Hydroxyl Anisole) on fresh and preserved beef meatballs. For this purpose, ground beef samples were divided into five treatment groups. They are treated as control, synthetic antioxidant, 0.1%, 0.2% and 0.3% Moringa oleifera leaf extract as T1, T2, T3, T4 and T5, respectively. Five kinds of meatballs were made and biscuit crushed and egg albumin was mixed with beef meatballs and cooking was practiced properly. Proximate analysis, sensory tests (color, flavor, tenderness, juiciness, overall acceptability), cooking loss, pH value, free fatty acids (FFA), thiobarbituric acid values (TBARS), peroxide value(POV) and microbiological examination were determined in order to evaluate the effect of Moringa oleifiera leaf extract as natural antioxidant & antimicrobial activities in comparing to BHA (Beta Hydroxyl Anisole) at first day before freezing and for maintaining meatballs qualities on the shelf life of beef meat balls stored for 60 days under frozen condition. Freezing temperature was -20˚C. Days of intervals of experiment were on 0, 15th, 30th, and 60th days. Dry matter content of all the treatment groups differ significantly (p<0.05). On the contrary, DM content increased significantly (p<0.05) with the advancement of different days of intervals. CP content of all the treatments were increased significantly (p<0.05) among the different treatment groups. EE content at different treatment levels differ significantly (p<0.05). Ash content at different treatment levels was also differ significantly (p<0.05). FFA values, TBARS, POV were decreased significantly (p<0.05) at different treatment levels. Color, odor, tenderness, juiciness, overall acceptability, raw PH, cooked pH were increased at different treatment levels significantly (p<0.05). The cooking loss (%) at different treatment levels were differ significantly (p<0.05). TVC (logCFU/g), TCC (logCFU/g) and TYMC (logCFU/g) was decreased significantly (p<0.05) at different treatment levels comparison to control. Considering CP, tenderness, juiciness, overall acceptability, cooking loss, FFA, POV, TBARS and microbial parameters it can be concluded that Moringa oleifera leaf extract at 0.1%, 0.2% and 0.3% can be used instead of 0.1% synthetic antioxidant BHA in beef meatballs.

Keywords: antioxidant, beef meatball, BHA, moringa leaf extract, quality

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Authors: Onuoha Ogbonnaya Gideon, Ishaq Hafsah Yusuf

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Introduction: Meat is a perishable food of good nutrition. Meat ranks among the most significant, nutritious, and favored food items available to most locals. It is a good source of protein (17-19%), depending on sources, and contains appreciable amounts of fat and moisture. However, it has a very short shelf life due mainly to its high moisture, fat, and other nutrient contents. Meat spoilage can result from microbial proliferation as well as inherent enzymes in the meat tissues. Bacteria contamination and permeability to both oxygen and water vapor are major concerns associated with spoilage of meat and its storage. Packaging is fundamental in the preservation and presentation of food. Red clay is a very common substance; hydrous aluminum phyllosilicate, sometimes with varying amounts of iron, magnesium, alkali metals, alkaline earth, and cation formed from sedimentary rocks. Furthermore, red clay is an extremely absorbent material and develops plasticity when wet due to the molecular film of water surrounding the clay particles but can become hard, impervious, brittle, and non-brittle and non-plastic when dry. In developing countries, the high cost of refrigeration technologies and most other methods of preserving meat are exorbitant and thus can be substituted with the less expensive and readily available red clay for the preservation of meat. Methodology: 1000g of lean meat was diced into cubes of 10g each. The sample was then divided into four groups labelled raw meat (RMC); raw in 10% brine solution (RMB), boiled meat (BMC), and fried meat (FMC). It was then encapsulated with 2mm thick red clay and then heated in a muffle furnace at a temperature of 600OC for 30min. The samples were kept on a bench top for 30 days, and a storage study was carried out. Results: Our findings showed a decrease in value during storage for the physiochemical properties of all the sample; pH values decreased [RMC (7.05-7.6), RMB (8.46-7.0), BMC (6.0-5.0), FMC (4.08-3.9)]; free fatty acid content decreased with storage time [RMC (32.6%-31%), RMB (30.2%-28.6%), BMC (30.5%-27.4%), FMC (25.6%-23.8%)]; total soluble solid value decreased [RMC16.20-15.07, RMB (17.22-16.04), BMC (17.05-15.54), FMC (15.3-14.9)]. Conclusion: This result shows that encapsulation with red clay reduced all the values analyzed and thus has the potential to extend the shelf life of stored meat.

Keywords: red clay, encapsulating, shelf life, physicochemical properties, lean meat

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Authors: Zachary Muthii Rukenya, James Mbaria, Peter Mbaabu, Kiama Stephen Gitahi, Ronald Onzago

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Aloe turkanensis is one of the widely used medicinal shrub and in Kenya the plant is mainly found in Baringo, Isiolo, Laikipia, Turkana and West Pokot Counties where it is used in ethno-medicine and ethno-veterinary medicine. The Turkana community uses the plant products to manage malaria, wounds, stomach ache, constipation, pain, skin infection, poultry diseases and retained afterbirth in cows. This evaluated the efficacy and safety of the plant obtained from Turkana County, Kenya. Preliminary data on the use of the plant in the county was collected through observation, photographing and interviews. A sample of the whole plant was harvested in Natira sublocation, in ex-Turkana west district in February 2012 after identification by Aloe-working group herbalists who voluntarily provided information on its medicinal uses. Botanical identification was done at Kenya Forest Research Centre in Karura where voucher specimen was deposited. Cold maceration using 70% methanol and distilled water was used for extraction. Bioassays were to determine the effects of the plant extracts on brine shrimp and selected bacterial and fungal cultures. The extracts were tested in-vitro activity against standard cultures of B. cereus (ATCC 11778), S. aureus (ATCC25923), P. aeroginosa (ATCC 27853), E. coli (ATCC 25922) and a human infections clinical isolate of C. albicans. The extracts of Aloe turkanensis inhibited the growth B. cereus (100-200 mg/ml), S. aureus (50-100 mg/ml), P. aeroginosa (200mg/ml), E. coli (400mg/ml) while C. albicans was not affected. The extracts also inhibited the growth of S. aureus and B. cereus with mean diameters of inhibition zones being 19.75±1 mm and 18.5±05 mm reapectively. Phytochemical screening showed the presence of alkaloids, tarpenoids, steroids, quinones, saponins and tannins in the plant extracts. The extract was found to be non-toxic at a concentration of 1000µg/ml with a 100% survival of Brine Shrimp larva. It was concluded that Aloe turkanensis growing the study area has metabolites that inhibit the growth of microorganisms and is however, there is need for further studies to validate the in-vivo bioactivity of the plant and more generate adequate toxicological data.to support conservation, value chain addition of its products and widespread use as a herbal remedy.

Keywords: Aloe turkanensis, bioactivity, cultivated, human infections

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Authors: Qunying Yuan, Manjula Bomma, Adrian Rhoden, Zhigang Xiao

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Selenium is an essential micronutrient for all mammals and plays an important role in maintaining human physiological functions. The potential applications of selenium as food supplements, cancer-prevention, antimicrobial and anti-inflammatory agents have been investigated in biomedicine and food sciences. Nanoscale of selenium is of particular interest due to its better biocompatibility, higher bioavailability, lower toxicity, more homogeneous distribution, and presumptive controlled release of substances. The objective of this study is to explore whether selenium nanoparticle (SeNP) has the potential to be used as a food preservative to reduce food spoilage. SeNPs were synthesized through ascorbic acid reduction of sodium selenite using the bovine serum albumin (BSA) as capping and stabilizing agent. The chemically synthesized SeNPs had a spherical conformation and a size of 22.8 ± 4.7 nm. FTIR analysis confirmed that the nanoparticles were covered with BSA. We further tested the antimicrobial activity of these SeNPs against common food-borne bacteria. Colony forming unit assay showed that SeNPs exhibited good inhibition on the growth of Listeria Monocytogens (ATCC15313), Staphylococcus epidermidis (ATCC 700583) starting at 0.5µg/mL, but only a moderate inhibitory effect on the growth of Staphylococcus aureus (ATCC12600) and Vibrio alginolyticus (ATCC 33787) at a concentration higher than 10µg/mL and 2.5µg/mL, respectively. There was a mild effect against the growth Salmonella enterica (ATCC19585) when the concentration reached 15µg/mL. No inhibition was observed in the growth of Enterococcus faecalis (ATCC 19433). Surprisingly, SeNPs appeared to promote the growth of Vibrio parahaemolyticus (ATCC43996) and Salmonella enterica (ATCC49284) at 30 µg/mL and above. Our preliminary data suggested that the chemically synthesized SeNPs may be able to inhibit some food-borne bacteria, and SeNP as a food preservative should be used with caution. We will explore the mechanisms of the inhibitory action of chemically synthesized SeNPs on bacterial growth and whether the SeNPs are able to inhibit the development of biofilm and antibiotic resistance.

Keywords: antimicrobial, food-borne bacteria, nanoparticles, selenium

Procedia PDF Downloads 93

Authors: Obadire F. O., Obadire, S. O., Adeoti R. F., Pirgozliev V.

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An experiment was conducted to determine the efficacy of utilizing African black plum seed nut (ABPNBD) meal on hematological and biochemical indices of broiler chicken ration formulated to substitute wheat offal. A total of 150- 1day-old, male Agrited birds were reared for 28 days of the experiment. The birds were assigned to five dietary treatments, with ten birds per treatment replicated 3 times. Experimental diets were formulated by supplementing the milled African black plum nut at (0, 5, 10, 12.5, and 15%) inclusion levels in the starter broiler’s ratio designated as T1 (control diet containing no ABPBD), Treatments (T2, 3,4 and 5) contained ABPNBD at 5, 10, 12.5, and 15%, respectively, in a completely randomized design. The hematological and biochemical indices of the birds were determined. The result revealed that all hematological parameters measured were significant (P <0.05) except for WBC. Increasing inclusion levels of ABPNBD decreased the PCV, HB, and RBC of the birds across the treatment groups. Birds fed 12.5 and 15% ABPNBD diets recorded the least of the parameters. The result of the serum biochemical indices showed significant (P < 0.05) influence for all parameters measured except for alanine transaminase (ALT), (AST), and creatinine. The total protein (TP), albumin, globulin, and glucose values were reduced across the treatment group as ABPNBD inclusion increased. Birds fed above 10% ABPNBD recorded the lowest value of TP, albumin, globulin, and glucose when compared with birds on a control diet and other treatments. The uric acid ranged from 3.85 to 2 .13 mmol/L, while creatinine ranged from 62.00 to 53.50 mmol/l. AST ranged between 8.50 u/l (5%) to 7.90 u/l (10%). ALT ranged between 7.50 u/l (12.5%) to 5.50 u/l (5 and 10%). In conclusion, dietary inclusion of African black plum up to 10% has no detrimental effect on the health of the starter chickens. Meanwhile, inclusion above 10% revealed a negative effect on some blood parameters measured. Therefore, African black plum should be supplemented with probable probiotics or subjected to different processing methods if to be used at a 15% inclusion level for optimal results.

Keywords: African black plum seed, starter broiler chickens, hematological and serum biochemical indices, (Vitex doniana)

Procedia PDF Downloads 52

Authors: Imane Naboulsi, Mansour Sobeh, Rachid Lamzira, Karim El Fakhouri, Widad Ben Bakrim, Chaimae Ramdani, Rachid Boulamtat, Mustapha El Bouhssini, Jane ward, Abdelaziz Yasri, Aziz Aboulmouhajir

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The wild cochineal Dactylopius opuntiae (Cockerell) (Hemiptera: Dactylopiidae) is the major insect pest of the prickly pear Opuntia ficus-indica (L.) in Morocco, which has causedenormous socio-economic and environmental losses to this crop in recent years. This study aimed to investigate the insecticidal potential of six aqueous (100% water), and methanolic (20/80 (v/v) MeOH/H2O) extracts obtained from aromatic and medicinal plants growing in arid and semi-arid regions of Morocco to control nymphs and adult females of D. opuntiae, under laboratory and greenhouse conditions. Under laboratory conditions, the aqueous extracts of Atriplex halimus at 5% caused significant mortality in nymphs with 71% four days after application and 88%on adult females of D. opuntiae8 days post-treatment. Under greenhouse conditions, the aqueous extract of A. halimus combined with black soap at 10 g/L showed the highest mortality rate of nymphs with 100%, 4 days after application. The adult females' mortality increased significantly to reach 83.75%,14 days after the second application of A. halimus aqueous extract at 5%. Phytochemical analysis of the water extract of A. halimus revealed a high content of saponins (24.09 ± 0.71 mg SSE/g DW) compared to other plant extracts, which was confirmed by LC-MS characterization that showed the presence of 36 triterpenoid saponin compounds (derived from oleic-12-en-28-oic acid), in addition to phytoecdysones, simple carboxylic acids, and flavonoids. These findings showed that using the aqueous extract of A. halimus as a biological pesticide could be incorporated into the management package to control the wild cochineal as a safe alternative to chemical insecticides.

Keywords: dactylopius opuntiae, opuntia ficus-indica L., plant extracts, toxicity, atriplex halimus, saponins

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Authors: Fuad Abdullah Alatawi

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Microbial infections-based diseases are a significant public health issue around the world, mainly when antibiotic-resistant bacterium types evolve. In this research, we explored the anti-bacterial and anti-cancer potency of iron-oxide (Fe₂O₃) nanoparticles prepared from F. macrocarpa fruit extract. The chemical composition of F. macrocarpa fruit extract was used as a reducing and capping agent for nanoparticles’ synthesis was examined by GC-MS/MS analysis. Then, the prepared nanoparticles were confirmed by various biophysical techniques, including X-ray powder diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), UV-Vis Spectroscopy, and Transmission Electron Microscopy (TEM) and Energy Dispersive Spectroscopy (EDAX), and Dynamic Light Scattering (DLS). Also, the antioxidant capacity of fruit extract was determined through 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS), Fluorescence Recovery After Photobleaching (FRAP), Superoxide Dismutase (SOD) assays. Furthermore, the cytotoxicity activities of Fe₂O₃ NPs were determined using the (3-(4, 5-dimethylthiazolyl-2)-2, 5-diphenyltetrazolium bromide) (MTT) test on MCF-7 cells. In the antibacterial assay, lethal doses of the Fe₂O₃NPs effectively inhibited the growth of gram-negative and gram-positive bacteria. The surface damage, ROS production, and protein leakage are the antibacterial mechanisms of Fe₂O₃NPs. Concerning antioxidant activity, the fruit extracts of F. macrocarpa had strong antioxidant properties, which were confirmed by DPPH, ABTS, FRAP, and SOD assays. In addition, the F. microcarpa-derived iron oxide nanomaterials greatly reduced the cell viability of (MCF-7). The GC-MS/MS analysis revealed the presence of 25 main bioactive compounds in the F. microcarpa extract. Overall, the finding of this research revealed that F. microcarpa-derived Fe₂O₃ nanoparticles could be employed as an alternative therapeutic agent to cure microbial infection and breast cancer in humans.

Keywords: ficus microcarpa, iron oxide, antibacterial activity, cytotoxicity

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Authors: Rezvan Ravanfar Haghighi, V. C. Vani, Suresh Perumal, Sabyasachi Chatterjee, Pratik Kumar

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X-ray attenuation coefficient [µ(E)] of any substance, for energy (E), is a sum of the contributions from the Compton scattering [ μCom(E)] and photoelectric effect [µPh(E)]. In terms of the, electron density (ρe) and the effective atomic number (Zeff) we have µCom(E) is proportional to [(ρe)fKN(E)] while µPh(E) is proportional to [(ρeZeffx)/Ey] with fKN(E) being the Klein-Nishina formula, with x and y being the exponents for photoelectric effect. By taking the sample's HU at two different excitation voltages (V=V1, V2) of the CT machine, we can solve for X=ρe, Y=ρeZeffx from these two independent equations, as is attempted in DECT inversion. Since µCom(E) and µPh(E) are both energy dependent, the coefficients of inversion are also dependent on (a) the source spectrum S(E,V) and (b) the detector efficiency D(E) of the CT machine. In the present paper we tabulate these coefficients of inversion for different practical manifestations of S(E,V) and D(E). The HU(V) values from the CT follow: <µ(V)>=<µw(V)>[1+HU(V)/1000] where the subscript 'w' refers to water and the averaging process <….> accounts for the source spectrum S(E,V) and the detector efficiency D(E). Linearity of μ(E) with respect to X and Y implies that (a) <µ(V)> is a linear combination of X and Y and (b) for inversion, X and Y can be written as linear combinations of two independent observations <µ(V1)>, <µ(V2)> with V1≠V2. These coefficients of inversion would naturally depend upon S(E, V) and D(E). We numerically investigate this dependence for some practical cases, by taking V = 100 , 140 kVp, as are used for cardiological investigations. The S(E,V) are generated by using the Boone-Seibert source spectrum, being superposed on aluminium filters of different thickness lAl with 7mm≤lAl≤12mm and the D(E) is considered to be that of a typical Si[Li] solid state and GdOS scintilator detector. In the values of X and Y, found by using the calculated inversion coefficients, errors are below 2% for data with solutions of glycerol, sucrose and glucose. For low Zeff materials like propionic acid, Zeffx is overestimated by 20% with X being within1%. For high Zeffx materials like KOH the value of Zeffx is underestimated by 22% while the error in X is + 15%. These imply that the source may have additional filtering than the aluminium filter specified by the manufacturer. Also it is found that the difference in the values of the inversion coefficients for the two types of detectors is negligible. The type of the detector does not affect on the DECT inversion algorithm to find the unknown chemical characteristic of the scanned materials. The effect of the source should be considered as an important factor to calculate the coefficients of inversion.

Keywords: attenuation coefficient, computed tomography, photoelectric effect, source spectrum

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Authors: Lorenza Sganzetta, Nunzia Borrelli

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The research intends to reflect on the current mapping of the Food Strategies, on the reasons why in the planning objectives panorama, such sustainability priorities are located in those geographic areas and on the evolutions of these priorities of the Mediterranean planning dispositions. The whirling population growth that is affecting global cities is causing an enormous challenge to conventional resource-intensive food production and supply and the urgent need to face food safety, food security and sustainability concerns. Urban or Territorial Food Strategies can provide an interesting path for the development of this new agenda within the imperative principle of sustainability. In the specific, it is relevant to explore what ‘sustainability’ means within these policies. Most of these plans include actions related to four main components and interpretations of sustainability that are food security and safety, food equity, environmental sustainability itself and cultural identity and, at the designing phase, they differ slightly from each other according to the degree of approximation to one of these dimensions. Moving from these assumptions, the article would analyze some practices and policies representatives of different Food Strategies of the world and focus on the Mediterranean ones, on the problems and negative externalities from which they start, on the first interventions that are implementing and on their main objectives. We will mainly use qualitative data from primary and secondary collections. So far, an essential observation could have been made about the relationship between these sustainability dimensions and geography. In statistical terms, the US and Canadian policies tended to devote a large research space to health issues and access to food; those northern European showed a special attention to the environmental issues and the shortening of the chain; and finally the policies that, even in limited numbers, were being developed in the Mediterranean basin, were characterized by a strong territorial and cultural imprint and their major aim was to preserve local production and the contact between the productive land and the end consumer. Recently, though, Mediterranean food planning strategies are focusing more on health related and food accessibility issues and analyzing our diets not just as a matter of culture and territorial branding but as tools for reducing public health costs and accessibility to fresh food for everyone. The article would reflect then on how Food Safety, Food Security and Health are entering the new agenda of the Mediterranean Food Strategies. The research hypothesis suggests that the economic crisis that in the last years invested both producers and consumers had a significant impact on the nutrition habits and on the redefinition of food poverty, even in the fatherland of the healthy Mediterranean diet. This trend and other variables influenced the orientation and the objectives of the food strategies.

Keywords: food security, food strategy, health, sustainability

Procedia PDF Downloads 223

Authors: Muhammad Suhail Ibrahim, Muhammad Nadeem, Muhammad Sultan, Uzair Sajjad, Khalid Hamid, Tahir Mahmood Qureshi, Sadaf Javaria

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Metabolic disorders, including hypertension, diabetes, cardiovascular disease etc., are major threats to public health and economy. Management and prevention of alarmingly increasing disorders have attracted researchers to explore natural barriers against these disorders. The objective of this study was to explore oats as a potential source of dietary fiber. Extraction of dietary was optimized by response surface methodology, and five indigenous oat cultivars, including SGD2011, Avon, SGD81, PD2LV65, and S2000, were also characterized for techno-functional characteristics, mineral composition and phytochemical quantification. These cultivars varied significantly (p < 0.05) for oil holding capacity, water saturation, and water holding capacity, respectively. SGD81 showed the highest oil-holding capacity, water-holding capacity, and water saturation due to the highest fraction of dietary fiber. The highest values of total phenolic contents, total flavonoid contents, total flavonol contents, 2, 2-Diphenyl-1-picrylhydrazyl radical scavenging activity, and anthocyanin were shown by SGD81, and SGD2011, respectively. All cultivars varied significantly (P<0.05) with respect to phytochemical quantification. Oat cultivars SGD81 and SGD2011 showed the best phenolic acid profile and can be effectively used as a source of nutraceuticals. Beyond the nutritional properties of oats, these also contribute and emerged as potential sources of dietary fiber and have gained attention as nutraceutical cereal crops. This approach offers oats as a natural means of dietary fiber to protect humans from alarmingly increasing metabolic disorders, and its extraction by sonication has made it a sustainable and eco-friendly strategy.

Keywords: oat cultivars, dietary fibers, mineral profile, antioxidant activity, color properties

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Authors: Mahadehe Hassan

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In most countries manufacturing, trading and distribution of gasoline and diesel fuels belongs to the most important sectors of national economy. For Bangladesh, a robust, well-functioning, secure and smartly managed national fuel distribution chain is an essential precondition for achieving Government top priorities in development and modernization of transportation infrastructure, protection of national environment and population health as well as, very importantly, securing due tax revenue for the State Budget. Bangladesh is a developing country with complex fuel supply network, high fuel taxes incidence and – till now - limited possibilities in application of modern, automated technologies for Government national fuel market control. Such environment allows dishonest physical and legal persons and organized criminals to build and profit from illegal fuel distribution schemes and fuel illicit trade. As a result, the market transparency and the country attractiveness for foreign investments, law-abiding economic operators, national consumers, State Budget and the Government ability to finance development projects, and the country at large suffer significantly. Research shows that over 50% of retail petrol stations in major agglomerations of Bangladesh sell adulterated fuels and/or cheat customers on the real volume of the fuel pumped into their vehicles. Other forms of detected fuel illicit trade practices include misdeclaration of fuel quantitative and qualitative parameters during internal transit and selling of non-declared and smuggled fuels. The aim of the study is to recommend the implementation of a National Fuel Distribution Integrity Program (FDIP) in Bangladesh to address and resolve fuel adulteration and illicit trade problems. The program should be customized according to the specific needs of the country and implemented in partnership with providers of advanced technologies. FDIP should enable and further enhance capacity of respective Bangladesh Government authorities in identification and elimination of all forms of fuel illicit trade swiftly and resolutely. FDIP high-technology, IT and automation systems and secure infrastructures should be aimed at the following areas (1) fuel adulteration, misdeclaration and non-declaration; (2) fuel quality and; (3) fuel volume manipulation at retail level. Furthermore, overall concept of FDIP delivery and its interaction with the reporting and management systems used by the Government shall be aligned with and support objectives of the Vision 2041 and Smart Bangladesh Government programs.

Keywords: fuel adulteration, octane, kerosene, diesel, petrol, pollution, carbon emissions

Procedia PDF Downloads 74

Authors: Hamid Abdulroof Saleh

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Background: Dioxins are one of the most widely distributed environmental pollutants. Dioxins consist of feedstock during the preparation of some industries, such as the paper industry as they can be produced in the atmosphere during the process of burning garbage and waste, especially medical waste. Dioxins can be found in the adipose tissues of animals in the food chain as well as in human breast milk. 2,3,7,8-Tetrachlorodibenzo-pdioxin (TCDD) is the most toxic component of a large group of dioxins. Humans are exposed to TCDD through contaminated food items like meat, fish, milk products, eggs etc. Recently, natural formulations relating to reducing or eliminating TCDD toxicity have been in focus. Ginger rhizome (Zingiber officinale R., family: Zingiberaceae), is used worldwide as a spice. Both antioxidative and androgenic activity of Z. officinale was reported in animal models. Researchers showed that ginger oil has dominative protective effect on DNA damage and might act as a scavenger of oxygen radical and might be used as an antioxidant. Aim of the work: The present study was undertaken to evaluate the toxic effect of TCDD on the structure and histoarchitecture of the testis and the protective role of co-administration of ginger root extract to prevent this toxicity. Materials & Methods: Male adult rats of Sprague-Dawley strain were assigned to four groups, eight rats in each; control group, dioxin treated group (given TCDD at the dose of 100 ng/kg Bwt/day by gavage), ginger treated group (given 50 mg/kg Bwt/day of ginger root extract by gavage), dioxin and ginger treated group (given TCDD at the dose of 100 ng/kg Bwt/day and 50 mg/kg Bwt/day of ginger root extract by gavages). After three weeks, rats were weighed and sacrificed where testis were removed and weighted. The testes were processed for routine paraffin embedding and staining. Tissue sections were examined for different morphometric and histopathological changes. Results: Dioxin administration showed a harmful effects in the body, testis weight and other morphometric parameters of the testis. In addition, it produced varying degrees of damage to the seminiferous tubules, which were shrunken and devoid of mature spermatids. The basement membrane was disorganized with vacuolization and loss of germinal cells. The co-administration of ginger root extract showed obvious improvement in the above changes and showed reversible morphometric and histopathological changes of the seminiferous tubules. Conclusion: Ginger root extract treatment in this study was successful in reversing all morphometric and histological changes of dioxin testicular damage. Therefore, it showed a protective effect on testis against dioxin toxicity.

Keywords: dioxin, ginger, rat, testis

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Authors: Rekha M. Y., Punith Kumar, Anshul Kamboj, Chandan Srivastava

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Coatings plays an important role in providing protection for a substrate and in improving the surface quality. Graphene/graphene oxide (GO) using in coating systems provides an environmental friendly solution towards protection against corrosion. Issues such as, lack of scale, high cost, low quality limits the practical application of graphene/GO as corrosion resistant coating material. One other way to employ these materials for corrosion protection is to incorporate them into coatings that are conventionally used for corrosion protection. Due to the extraordinary properties of graphene/GO, it has been demonstrated that the coatings containing graphene/GO are more corrosion resistant than pure metal/alloy coatings. In the present work, Cr-graphene and SnZn-GO composite coatings were investigated in enhancing the corrosion resistant property when compared to pure Cr coating and pure SnZn coating respectively. All the coatings were electrodeposited over mild-steel substrate. Graphene and GO were synthesized by electrochemical exfoliation method and modified Hummers’ method respectively. In Cr coatings, the microstructural study revealed that the addition of formic acid in the coatings reduced the number of cracks in the coatings. Further addition of graphene in Cr coating enhanced the Cr coating’s morphology. Chemically synthesized ZnO nanoparticles were also embedded in the as-deposited Cr and Cr-graphene coatings to enhance the adhesion of the coating, to improve the surface finish and to increase the corrosion resistant property of the coatings. Diffraction analysis revealed that the addition of graphene also altered the texture of the Cr coatings. In SnZn alloy coatings, the morphological and topographical characterization revealed that the relative smoothness and compactness of the coatings increased with increase in the addition of GO in the coatings. The microstructural investigation revealed large-scale segregation of Zn-rich and Sn-rich phases in the pure SnZn coating. However, in SnZn-GO composite coating the uniform distribution of Zn phase in the Sn-rich matrix was observed. This distribution caused the early and uniform formation of ZnO, which is the corrosion product, yielding better corrosion resistance for the SnZn-GO composite coatings as compared to pure SnZn coating. A significant improvement in corrosion resistance in terms of reduction in corrosion current and corrosion rate and increase in the polarization resistance was observed in Cr coating containing graphene and in SnZn coatings containing GO.

Keywords: coatings, corrosion, electrodeposition, graphene, graphene-oxide

Procedia PDF Downloads 181

Authors: Lakmini Wijesooriya, Vicki Chalker, Jessica Day, Priyantha Perera, N. P. Sunil-Chandra

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M. pneumoniae has been identified as an etiology for exacerbation of asthma (EQA), although viruses play a major role in EOA. M. pneumoniae infection is treated empirically with macrolides, and its antibiotic sensitivity is not detected routinely. Characterization of the organism by genotyping and determination of macrolide resistance is important epidemiologically as it guides the empiric antibiotic treatment. To date, there is no such characterization of M. pneumoniae performed in Sri Lanka. The present study describes the characterization of M. pneumoniae detected from a child with EOA following a screening of 100 children with EOA. Of the hundred children with EOA, M. pneumoniae was identified only in one child by Real-Time polymerase chain reaction (PCR) test for identifying the community-acquired respiratory distress syndrome (CARDS) toxin nucleotide sequences. The M. pneumoniae identified from this patient underwent detection of macrolide resistance via conventional PCR, amplifying and sequencing the region of the 23S rDNA gene that contains single nucleotide polymorphisms that confer resistance. Genotyping of the isolate was performed via nested Multilocus Sequence Typing (MLST) in which eight (8) housekeeping genes (ppa, pgm, gyrB, gmk, glyA, atpA, arcC, and adk) were amplified via nested PCR followed by gene sequencing and analysis. As per MLST analysis, the M. pneumoniae was identified as sequence type 14 (ST14), and no mutations that confer resistance were detected. Resistance to macrolides in M. pneumoniae is an increasing problem globally. Establishing surveillance systems is the key to informing local prescriptions. In the absence of local surveillance data, antibiotics are started empirically. If the relevant microbiological samples are not obtained before antibiotic therapy, as in most occasions in children, the course of antibiotic is completed without a microbiological diagnosis. This happens more frequently in therapy for M. pneumoniae which is treated with a macrolide in most patients. Hence, it is important to understand the macrolide sensitivity of M. pneumoniae in the setting. The M. pneumoniae detected in the present study was macrolide sensitive. Further studies are needed to examine a larger dataset in Sri Lanka to determine macrolide resistance levels to inform the use of macrolides in children with EOA. The MLST type varies in different geographical settings, and it also provides a clue to the existence of macrolide resistance. The present study enhances the database of the global distribution of different genotypes of M. pneumoniae as this is the first such characterization performed with the increased number of samples to determine macrolide resistance level in Sri Lanka. M. pneumoniae detected from a child with exacerbation of asthma in Sri Lanka was characterized as ST14 by MLST and no mutations that confer resistance were detected.

Keywords: mycoplasma pneumoniae, Sri Lanka, characterization, macrolide resistance

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Authors: V. Mani Rathnam, Giridhar Madras

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Fossil fuels are depleting rapidly as the demand for energy, and its allied chemicals are continuously increasing in the modern world. Therefore, sustainable renewable energy sources based on non-edible oils are being explored as a viable option as they do not compete with the food commodities. Oils such as castor oil are rich in fatty acids and thus can be used for the synthesis of biodiesel, bio-lubricants, and many other fine industrial chemicals. There are several processes available for the synthesis of different chemicals obtained from the castor oil. One such process is the transesterification of castor oil, which results in a mixture of fatty acid methyl esters. The main products in the above reaction are methyl ricinoleate and methyl 10-undecenoate. To separate these compounds, supercritical carbon dioxide (SCCO₂) was used as a green solvent. SCCO₂ was chosen as a solvent due to its easy availability, non-toxic, non-flammable, and low cost. In order to design any separation process, the preliminary requirement is the solubility or phase equilibrium data. Therefore, the solubility of a mixture of methyl ricinoleate with methyl 10-undecenoate in SCCO₂ was determined in the present study. The temperature and pressure range selected for the investigation were T = 313 K to 333 K and P = 10 MPa to 18 MPa. It was observed that the solubility (mol·mol⁻¹) of methyl 10-undecenoate varied from 2.44 x 10⁻³ to 8.42 x 10⁻³ whereas it varied from 0.203 x 10⁻³ to 6.28 x 10⁻³ for methyl ricinoleate within the chosen operating conditions. These solubilities followed a retrograde behavior (characterized by the decrease in the solubility values with the increase in temperature) throughout the range of investigated operating conditions. An association theory model, coupled with regular solution theory for activity coefficients, was developed in the present study. The deviation from the experimental data using this model can be quantified using the average absolute relative deviation (AARD). The AARD% for the present compounds is 4.69 and 8.08 for methyl 10-undecenoate and methyl ricinoleate, respectively in a mixture of methyl ricinoleate and methyl 10-undecenoate. The maximum solubility enhancement of 32% was observed for the methyl ricinoleate in a mixture of methyl ricinoleate and methyl 10-undecenoate. The highest selectivity of SCCO₂ was observed to be 12 for methyl 10-undecenoate in a mixture of methyl ricinoleate and methyl 10-undecenoate.

Keywords: association theory, liquid mixtures, solubilities, supercritical carbon dioxide

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Authors: Laribi-Habchi Hasiba, Bouanane-Darenfed Amel, Drouiche Nadjib, Pausse André, Mameri Nabil

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Chitin, a linear 1, 4-linked N-acetyl-d-glucosamine (GlcNAc) polysaccharide is the major structural component of fungal cell walls, insect exoskeletons and shells of crustaceans. It is one of the most abundant naturally occurring polysaccharides and has attracted tremendous attention in the fields of agriculture, pharmacology and biotechnology. Each year, a vast amount of chitin waste is released from the aquatic food industry, where crustaceans (prawn, crab, Shrimp and lobster) constitute one of the main agricultural products. This creates a serious environmental problem. This linear polymer can be hydrolyzed by bases, acids or enzymes such as chitinase. In this context an extracellular chitinase (ChiA-65) was produced and purified from a newly isolated LHH100. Pure protein was obtained after heat treatment and ammonium sulphate precipitation followed by Sephacryl S-200 chromatography. Based on matrix assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF/MS) analysis, the purified enzyme is a monomer with a molecular mass of 65,195.13 Da. The sequence of the 27 N-terminal residues of the mature ChiA-65 showed high homology with family-18 chitinases. Optimal activity was achieved at pH 4 and 75◦C. Among the inhibitors and metals tested p-chloromercuribenzoic acid, N-ethylmaleimide, Hg2+ and Hg + completelyinhibited enzyme activity. Chitinase activity was high on colloidal chitin, glycol chitin, glycol chitosane, chitotriose and chitooligosaccharide. Chitinase activity towards synthetic substrates in the order of p-NP-(GlcNAc) n (n = 2–4) was p-NP-(GlcNAc)2> p-NP-(GlcNAc)4> p-NP-(GlcNAc)3. Our results suggest that ChiA-65 preferentially hydrolyzed the second glycosidic link from the non-reducing end of (GlcNAc) n. ChiA-65 obeyed Michaelis Menten kinetics the Km and kcat values being 0.385 mg, colloidal chitin/ml and5000 s−1, respectively. ChiA-65 exhibited remarkable biochemical properties suggesting that this enzyme is suitable for bioconversion of chitin waste.

Keywords: Bacillus licheniformis LHH100, characterization, extracellular chitinase, purification

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Authors: Palaniyandi Karuppaiya, Hsin Sheng Tsay, Fang Chen

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Medicinal herbs do represent a huge and noteworthy reservoir for novel anticancer drugs discovery. Dysosma pleiantha (Hance) Woodson (Berberidaceae), one of the oldest traditional Chinese medicinal herb, highly prized by the mountain tribes of Taiwan and China for its medicinal properties contained pharmaceutically important antitumor compounds podophyllotoxin, quercetin and kaempferol. Among lignans, podophyllotoxin is an active antitumor compound and has now been modified to produce clinically useful drugs etoposide and teniposide. In recent years, natural populations of D. peliantha have declined considerably due to anthropogenic activities such as habitat destruction and commercial exploitation for medicinal applications. As to its overall conservation status, D. pleiantha has been ranked as threatened on the China Species Red List. In the present study, an efficient in vitro callus culture system of D. pleiantha was established on Gamborg’s medium with various combinations and concentrations of different auxins and cytokinins under dark condition. Best callus induction was recorded in 2 mg/L 2, 4 - Dichlorophenoxyacetic acid (2,4-D) along with 0.2 mg/L kinetin and the maximum callus proliferation was achieved at 1 mg/L 2,4-D. Among the explants tested, maximum callus induction (86 %) was achieved from tender leaves. Hence, in subsequent experiments, leaf callus was further investigated for suitable callus biomass and production level of anticancer compounds under the influence of different additives. A maximum fresh callus biomass (8.765 g) was recorded in callus proliferation medium contained 500 mg/L casein hydrolysate. High performance liquid chromatography results revealed that the addition of different concentrations of peptone (1, 2 and 4 g/L) in callus proliferation medium enhanced podophyllotoxin (16 fold), quercetin (12 fold) and kaempferol (5 fold) accumulation than control. Thus, the established in vitro callus culture under the influence of different additives may offer an alternative source of enhanced production of podophyllotoxin, kaempferol and quecertin without harming natural plant population.

Keywords: dysosma pleiantha, kaempferol, podophyllotoxin, quercetin

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Authors: Bruna Lima Gomes, Vanessa Caroline De Barros Bonato, Luciano Freschi, Eduardo Purgatto

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Plant hormones are long known to be tightly associated with fruit development and are involved in controlling various aspects of fruit ripening. For fleshy fruits, ripening is characterized for changes in texture, color, aroma and other parameters that markedly contribute to its quality. Ethylene is one of the major players regulating the ripening-related processes, but emerging evidences suggest that auxin is also part of this dynamic control. Thus, the aim of this study was providing new insights into the auxin role during ripening and the hormonal interplay between auxin and ethylene. For that, tomato fruits (Micro-Tom) were collected at mature green stage and separated in four groups: one for indole-3-acetic acid (IAA) treatment, one for ethylene, one for a combination of IAA and ethylene, and one for control. Hormone solution was injected through the stylar apex, while mock samples were injected with buffer only. For ethylene treatments, fruits were exposed to gaseous hormone. Then, fruits were left to ripen under standard conditions and to assess ripening development, hue angle was reported as color indicator and ethylene production was measured by gas chromatography. The transcript levels of three ripening-related ethylene receptors (LeETR3, LeETR4 and LeETR6) were evaluated by RT-qPCR. Results showed that ethylene treatment induced ripening, stimulated ethylene production, accelerated color changes and induced receptor expression, as expected. Nonetheless, auxin treatment showed the opposite effect once fruits remained green for longer time than control group and ethylene perception has changed, taking account the reduced levels of receptor transcripts. Further, treatment with both hormones revealed that auxin effect in delaying ripening was predominant, even with higher levels of ethylene. Altogether, the data suggest that auxin modulates several aspects of the tomato fruit ripening modifying the ethylene perception. The knowledge about hormonal control of fruit development will help design new strategies for effective manipulation of ripening regarding fruit quality and brings a new level of complexity on fruit ripening regulation.

Keywords: ethylene, auxin, fruit ripening, hormonal crosstalk

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Authors: Pooria Norouzi, Nicholas Tsang, Adam van der Goes, Joseph Yu, Douglas Zheng, Sirine Maleej

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In this study, virtual meters will be designed and used for energy balance measurements of an air handling unit (AHU). The method aims to replace traditional physical sensors in heating, ventilation, and air conditioning (HVAC) systems with simulated virtual meters. Due to the inability to manage and monitor these systems, many HVAC systems have a high level of inefficiency and energy wastage. Virtual meters are implemented and applied in an actual HVAC system, and the result confirms the practicality of mathematical sensors for alternative energy measurement. While most residential buildings and offices are commonly not equipped with advanced sensors, adding, exploiting, and monitoring sensors and measurement devices in the existing systems can cost thousands of dollars. The first purpose of this study is to provide an energy consumption rate based on available sensors and without any physical energy meters. It proves the performance of virtual meters in HVAC systems as reliable measurement devices. To demonstrate this concept, mathematical models are created for AHU-07, located in building NE01 of the British Columbia Institute of Technology (BCIT) Burnaby campus. The models will be created and integrated with the system’s historical data and physical spot measurements. The actual measurements will be investigated to prove the models' accuracy. Based on preliminary analysis, the resulting mathematical models are successful in plotting energy consumption patterns, and it is concluded confidently that the results of the virtual meter will be close to the results that physical meters could achieve. In the second part of this study, the use of virtual meters is further assisted by artificial intelligence (AI) in the HVAC systems of building to improve energy management and efficiency. By the data mining approach, virtual meters’ data is recorded as historical data, and HVAC system energy consumption prediction is also implemented in order to harness great energy savings and manage the demand and supply chain effectively. Energy prediction can lead to energy-saving strategies and considerations that can open a window in predictive control in order to reach lower energy consumption. To solve these challenges, the energy prediction could optimize the HVAC system and automates energy consumption to capture savings. This study also investigates AI solutions possibility for autonomous HVAC efficiency that will allow quick and efficient response to energy consumption and cost spikes in the energy market.

Keywords: virtual meters, HVAC, artificial intelligence, energy consumption prediction

Procedia PDF Downloads 105

Authors: Tom Nakotte, Hongmei Luo

Abstract:

Lead chalcogenide-based (PbS, PbSe, and PbTe) quantum dots (QDs) were synthesized for the purpose of implementing them in radiation detectors. Pb based materials have long been of interest for gamma and x-ray detection due to its high absorption cross section and Z number. The emphasis of the studies was on exploring how to control charge carrier transport within thin films containing the QDs. The properties of QDs itself can be altered by changing the size, shape, composition, and surface chemistry of the dots, while the properties of carrier transport within QD films are affected by post-deposition treatment of the films. The QDs were synthesized using colloidal synthesis methods and films were grown using multiple film coating techniques, such as spin coating and doctor blading. Current QD radiation detectors are based on the QD acting as fluorophores in a scintillation detector. Here the viability of using QDs in solid-state radiation detectors, for which the incident detectable radiation causes a direct electronic response within the QD film is explored. Achieving high sensitivity and accurate energy quantification in QD radiation detectors requires a large carrier mobility and diffusion lengths in the QD films. Pb chalcogenides-based QDs were synthesized with both traditional oleic acid ligands as well as more weakly binding oleylamine ligands, allowing for in-solution ligand exchange making the deposition of thick films in a single step possible. The PbS and PbSe QDs showed better air stability than PbTe. After precipitation the QDs passivated with the shorter ligand are dispersed in 2,6-difloupyridine resulting in colloidal solutions with concentrations anywhere from 10-100 mg/mL for film processing applications, More concentrated colloidal solutions produce thicker films during spin-coating, while an extremely concentrated solution (100 mg/mL) can be used to produce several micrometer thick films using doctor blading. Film thicknesses of micrometer or even millimeters are needed for radiation detector for high-energy gamma rays, which are of interest for astrophysics or nuclear security, in order to provide sufficient stopping power.

Keywords: colloidal synthesis, lead chalcogenide, radiation detectors, quantum dots

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Authors: Ameni Mejri, Moufida Hajjaj, Salem Hasnaoui, Ridha Bouallegue

Abstract:

The technology advances have most lately made the millimeter wave (mmWave) communication possible. Due to the huge amount of spectrum that is available in MmWave frequency bands, this promising candidate is considered as a key technology for the deployment of 5G cellular networks. In order to enhance system capacity and achieve spectral efficiency, very large antenna arrays are employed at mmWave systems by exploiting array gain. However, it has been shown that conventional beamforming strategies are not suitable for mmWave hardware implementation. Therefore, new features are required for mmWave cellular applications. Unlike traditional multiple-input-multiple-output (MIMO) systems for which only digital precoders are essential to accomplish precoding, MIMO technology seems to be different at mmWave because of digital precoding limitations. Moreover, precoding implements a greater number of radio frequency (RF) chains supporting more signal mixers and analog-to-digital converters. As RF chain cost and power consumption is increasing, we need to resort to another alternative. Although the hybrid precoding architecture has been regarded as the best solution based on a combination between a baseband precoder and an RF precoder, we still do not get the optimal design of hybrid precoders. According to the mapping strategies from RF chains to the different antenna elements, there are two main categories of hybrid precoding architecture. Given as a hybrid precoding sub-array architecture, the partially-connected structure reduces hardware complexity by using a less number of phase shifters, whereas it sacrifices some beamforming gain. In this paper, we treat the hybrid precoder design in mmWave MIMO systems as a problem of matrix factorization. Thus, we adopt the alternating minimization principle in order to solve the design problem. Further, we present our proposed algorithm for the partially-connected structure, which is based on the iterative hard thresholding method. Through simulation results, we show that our hybrid precoding algorithm provides significant performance gains over existing algorithms. We also show that the proposed approach reduces significantly the computational complexity. Furthermore, valuable design insights are provided when we use the proposed algorithm to make simulation comparisons between the hybrid precoding partially-connected structure and the fully-connected structure.

Keywords: alternating minimization, hybrid precoding, iterative hard thresholding, low-complexity, millimeter wave communication, partially-connected structure

Procedia PDF Downloads 321