Search results for: methanol oxidation

Authors: Julia R. Beulig, Stefan Ohla, Detlev Belder

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In contrast to off-line analytical methods, lab-on-a-chip technology delivers direct information about the observed reaction. Therefore, microfluidic devices make an important scientific contribution, e.g. in the field of synthetic chemistry. Herein, the rapid generation of analytical data can be applied for the optimization of chemical reactions. These microfluidic devices enable a fast change of reaction conditions as well as a resource saving method of operation. In the presented work, we focus on the investigation of multiphase regimes, more specifically on a biphasic microfluidic droplet systems. Here, every single droplet is a reaction container with customized conditions. The biggest challenge is the rapid qualitative and quantitative readout of information as most detection techniques for droplet systems are non-specific, time-consuming or too slow. An exception is the electrospray mass spectrometry (ESI-MS). The combination of a reaction screening platform with a rapid and specific detection method is an important step in droplet-based microfluidics. In this work, we present a novel approach for synthesis optimization on the nanoliter scale with direct ESI-MS detection. The development of a droplet-based microfluidic device, which enables the modification of different parameters while simultaneously monitoring the effect on the reaction within a single run, is shown. By common soft- and photolithographic techniques a polydimethylsiloxane (PDMS) microfluidic chip with different functionalities is developed. As an interface for the MS detection, we use a steel capillary for ESI and improve the spray stability with a Teflon siphon tubing, which is inserted underneath the steel capillary. By optimizing the flow rates, it is possible to screen parameters of various reactions, this is exemplarity shown by a Domino Knoevenagel Hetero-Diels-Alder reaction. Different starting materials, catalyst concentrations and solvent compositions are investigated. Due to the high repetition rate of the droplet production, each set of reaction condition is examined hundreds of times. As a result, of the investigation, we receive possible reagents, the ideal water-methanol ratio of the solvent and the most effective catalyst concentration. The developed system can help to determine important information about the optimal parameters of a reaction within a short time. With this novel tool, we make an important step on the field of combining droplet-based microfluidics with organic reaction screening.

Keywords: droplet, mass spectrometry, microfluidics, organic reaction, screening

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Authors: Leonardo Parra, Daniel Martínez, Jorge Pizarro, Fernando Ortega, Manuel Chacón-Fuentes, Andrés Quiroz

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Control of Dalaca pallens or blackworms, one of the most important hypogeous pest in grassland in southern Chile, is based on the use of broad-spectrum insecticides such as organophosphates and pyrethroids. However, the rapid development of insecticide resistance in field populations of this insect and public concern over the environmental impact of these insecticides has resulted in the search for other control methods. Specifically, the use of endophyte fungi for controlling pest has emerged as an interesting and promising strategy. Endophytes from ryegrass (Lolium perenne), establish a biotrophic relationship with the host, defined as mutualistic symbiosis. The plant-fungi association produces alkaloids where peramine is the main toxic substance against Listronotus bonariensis, the most important epigean pest of ryegrass. Nevertheless, the effect of peramina on others pest insects, such as D. pallens, to our knowledge has not been studied, and also its possible metabolization in the body of the larvae. Therefore, we addressed the following research question: Do larvae of D. pallens store peramine after consumption of ryegrass endophyte infected (E+)? For this, specimens of blackworms were fed with ryegrass plant of seven experimental lines and one commercial cultivar endophyte free (E-) sown at the Instituto de Investigaciones Agropecuarias Carillanca (Vilcún, Chile). Once the feeding period was over, ten larvae of each treatment were examined. Individuals were dissected, and their gut was removed to exclude any influence of remaining material. The rest of the larva's body was dried at 60°C by 24-48 h and ground into a fine powder using a mortar. 25 mg of dry powder was transferred to a microcentrifuge tube and extracted in 1 mL of a mixture of methanol:water:formic acid. Then, the samples were centrifuged at 16,000 rpm for 3 min, and the supernatant was colected and injected in the liquid chromatography of high resolution (HPLC). The results confirmed the presence of peramine in the larva's body of D. pallens. The insects that fed the experimental lines LQE-2 and LQE-6 were those where peramine was present in high proportion (0.205 and 0.199 ppm, respectively); while LQE-7 and LQE-3 obtained the lowest concentrations of the alkaloid (0.047 and 0.053 ppm, respectively). Peramine was not detected in the insects when the control cultivar Jumbo (E-) was tested. These results evidenced the storage and metabolism of peramine during consumption of the larvae. However, the effect of this alkaloid present in 'future ryegrass cultivars' (LQE-2 and LQE-6) on the performance and survival of blackworms must be studied and confirmed experimentally.

Keywords: blackworms, HPLC, alkaloid, pest

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Authors: Sanjay Kumar, Dinesh Pathak, Sudhir Saralch

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Copper oxide is a semiconductor that has been studied for several reasons such as the natural abundance of starting material copper (Cu); the easiness of production by Cu oxidation; their non-toxic nature and the reasonably good electrical and optical properties. Copper oxide is well-known as cuprite oxide. The cuprite is p-type semiconductors having band gap energy of 1.21 to 1.51 eV. As a p-type semiconductor, conduction arises from the presence of holes in the valence band (VB) due to doping/annealing. CuO is attractive as a selective solar absorber since it has high solar absorbency and a low thermal emittance. CuO is very promising candidate for solar cell applications as it is a suitable material for photovoltaic energy conversion. It has been demonstrated that the dip technique can be used to deposit CuO films in a simple manner using metallic chlorides (CuCl₂.2H₂O) as a starting material. Copper oxide films are prepared using a methanolic solution of cupric chloride (CuCl₂.2H₂O) at three baking temperatures. We made three samples, after heating which converts to black colour. XRD data confirm that the films are of CuO phases at a particular temperature. The optical band gap of the CuO films calculated from optical absorption measurements is 1.90 eV which is quite comparable to the reported value. Dip technique is a very simple and low-cost method, which requires no sophisticated specialized setup. Coating of the substrate with a large surface area can be easily obtained by this technique compared to that in physical evaporation techniques and spray pyrolysis. Another advantage of the dip technique is that it is very easy to coat both sides of the substrate instead of only one and to deposit otherwise inaccessible surfaces. This method is well suited for applying coating on the inner and outer surfaces of tubes of various diameters and shapes. The main advantage of the dip coating method lies in the fact that it is possible to deposit a variety of layers having good homogeneity and mechanical and chemical stability with a very simple setup. In this paper, the CuO thin films preparation by dip coating method and their characterization will be presented.

Keywords: absorber material, cupric oxide, dip coating, thin film

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Authors: Inayat Shah, Muhammad Omar Malik, Ghareeb Alshuwaier, Ronald H. Baxendale

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Background: The balance between angiogenesis and angiostasis is important in growth and developmental processes in the body. Angiogenic and angiostatic mediators control this balance. Endostatin is one of the prominent angiostatic mediators. The marked angiostatic effect of endostatin includes inhibiting endothelial cell migration, proliferation and apoptosis. Physical activity decreases the risk and development of many angiogenesis related health problems including atherosclerosis and numerous cancers. Physiological influences of different physical activities on plasma endostatin concentration are controversial and not completely clear. Moreover, correlation of physical characteristics and metabolic predictors during physical activity on circulating endostatin is indistinct and poorly speculated. The study aimed to determine the effects of mild, moderate and vigorous exercise on the concentration of endostatin in plasma. Methodology: 22 participants, 16 males (age = 30.6 ± 7.8 years) and 6 females (age = 26.5 ± 5 years) were recruited. Weekly session of different intensities exercise based on the predicted maximum heart of the participants [60%(low), 70% (moderate) and 80% (vigorous)] were carried out. The duration and work rate for each participant was determined through sub-maximal exercise. Standardization of the session was done on total energy expenditure of the participants per session. One pre exercise and two post exercise samples were taken at intervals of 10 and 60 minutes. Results: Pre-exercise mean endostatin was 101 ± 20 ng/dl. Low intensity exercise insignificantly decreased the endostatin concentration in plasma at 10 and 60 minutes 97 ± 20 ng/dl (p= 0.5), 98 ± 23 ng/dl (p= 0.8)). However, moderate (p= 0.022, 0.004) and vigorous intensities (p ≤ 0.001, 0.02) increased the endostatin concentrations significantly at both 10 and 60 minutes intervals respectively. The effects were not significantly influenced by gender, exercise mode (walking vs. running), components of exercise (HR, Speed, Gradients, distance, duration) or metabolism during exercise (VO₂ max, VCO₂, RER, energy expenditure, rate of carbohydrate or fats oxidation). Conclusion: Low intensity exercises did not influence endostatin concentration. However, moderate to high intensity exercises significantly increase endostatin concentration and may have potential benefits.

Keywords: angiogenesis, exercise, endostatin, physical activity

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Authors: Minhal Abidi, Moinuddin

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Diabetes mellitus (DM) induced metabolic abnormalities causes oxidative stress which leads to the pathogenesis of complications associated with diabetes like retinopathy, nephropathy periodontitis etc. Combination of glycation and oxidation 'glycoxidation' occurs when oxidative reactions affect the early state of glycation products. Low density lipoprotein (LDL) is prone to glycoxidative attack by sugars and methylglyoxal (MGO) being a strong glycating agent may have severe impact on its structure and consequent role in diabetes. Pro-inflammatory cytokines like IL1β and TNFα produced by the action of gram negative bacteria in periodontits (PD) can in turn lead to insulin resistance. This work discusses modifications to LDL as a result of glycoxidation. The changes in the protein molecule have been characterized by various physicochemical techniques and the immunogenicity of the modified molecules was also evaluated as they presented neo-epitopes. Binding of antibodies present in diabetes patients to the native and glycated LDL has been evaluated. Role of modified epitopes in the generation of antibodies in diabetes and periodontitis has been discussed. The structural perturbations induced in LDL were analyzed by UV–Vis, fluorescence, circular dichroism and FTIR spectroscopy, molecular docking studies, thermal denaturation studies, Thioflavin T assay, isothermal titration calorimetry, comet assay. MALDI-TOF, ketoamine moieties, carbonyl content and HMF content were also quantitated in native and glycated LDL. IL1β and TNFα levels were also measured in the type 2 DM and PD patients. We report increased carbonyl content, ketoamine moieties and HMF content in glycated LDL as compared to native analogue. The results substantiate that in hyperglycemic state MGO modification of LDL causes structural perturbations making the protein antigenic which could obstruct normal physiological functions and might contribute in the development of secondary complications in diabetic patients like periodontitis.

Keywords: advanced glycation end products, diabetes mellitus, glycation, glycoxidation, low density lipoprotein, periodontitis

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Authors: Ntokozo Dambuza, Maryna Van De Venter, Trevor Koekemoer

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Oxidative stress contributes to the pathogenesis of many diseases and consequently antioxidant therapy has attracted much attention as a potential therapeutic strategy. Regardless of the quantities ingested, antioxidants need to reach the diseased tissues at concentrations sufficient to combat oxidative stress. Bioavailability is thus a defining criterion for the therapeutic efficacy of antioxidants. In addition, therapeutic antioxidants must possess biologically relevant characteristics which can target the specific molecular mechanisms responsible for disease related oxidative stress. While many chemical antioxidant assays are available to quantify antioxidant capacity, they relate poorly to the biological environment and provide no information as to the bioavailability. The present comparative study thus aims to characterise green and fermented rooibos extracts, well recognized for their exceptional antioxidant capacity, in terms of antioxidant bioavailability and efficacy in a disease relevant cellular setting. Chinese green tea antioxidant activity was also evaluated. Chemical antioxidant assays (FRAP, DPPH and ORAC) confirmed the potent antioxidant capacity of both green and fermented rooibos, with green rooibos possessing antioxidant activity superior to that of fermented rooibos and Chinese green tea. Bioavailability was assessed using the PAMPA assay and the results indicate that green and fermented rooibos have a permeation coefficient of 5.7 x 10-6 and 6.9 x 10-6 cm/s, respectively. Chinese green tea permeability coefficient was 8.5 x 10-6 cm/s. These values were comparable to those of rifampicin, which is known to have a high permeability across intestinal epithelium with a permeability coefficient of 5 x 10 -6 cm/s. To assess the antioxidant efficacy in a cellular context, U937 and red blood cells were pre-treated with rooibos and Chinese green tea extracts in the presence of a dye DCFH-DA and then exposed to oxidative stress. Green rooibos exhibited highest activity with an IC50 value of 29 μg/ml and 70 μg/ml, when U937 and red blood cells were exposed oxidative stress, respectively. Fermented rooibos and Chinese green tea had IC50 values of 61 μg/ml and 57 μg/ml for U937, respectively, and 221 μg/ml and 405 μg/ml for red blood cells, respectively. These results indicate that fermented and green rooibos extracts were able to permeate the U937 cells and red blood cell membrane and inhibited oxidation of DCFH-DA to a fluorescent DCF within the cells.

Keywords: rooibos, antioxidants, permeability, bioavailability

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Authors: Naijin Wu, Peizhong Li, Haijian Wang, Wenxia Wei, Yun Song

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Chlorinated aliphatic hydrocarbons (CAHs) pollution poses a severe threat to human health and is persistent in groundwater. Although chemical reduction or bioremediation is effective, it is still hard to achieve their complete and rapid dechlorination. Recently, the combination of zero-valent iron and biostimulation has been considered to be one of the most promising strategies, but field studies of this technology are scarce. In a typical site contaminated by various types of CAHs, basic physicochemical parameters of groundwater, CAHs and their product concentrations, and microbial abundance and diversity were monitored after a remediation slurry containing both micron zero-valent iron (mZVI) and biostimulation components were directly injected into the aquifer. Results showed that groundwater could form and keep low oxidation-reduction potential (ORP), a neutral pH, and anoxic conditions after different degrees of fluctuations, which was benefit for the reductive dechlorination of CAHs. The injection also caused an obvious increase in the total organic carbon (TOC) concentration and sulfate reduction. After 253 days post-injection, the mean concentration of total chlorinated ethylene (CEE) from two monitoring wells decreased from 304 μg/L to 8 μg/L, and total chlorinated ethane (CEA) decreased from 548 μg/L to 108 μg/L. Occurrence of chloroethane (CA) suggested that hydrogenolysis dechlorination was one of the main degradation pathways for CEA, and also hints that biological dechlorination was activated. A significant increase of ethylene at day 67 post-injection indicated that dechlorination was complete. Additionally, the total bacterial counts increased by 2-3 orders of magnitude after 253 days post-injection. And the microbial species richness decreased and gradually changed to anaerobic/fermentative bacteria. The relative abundance of potential degradation bacteria increased corresponding to the degradation of CAHs. This work demonstrates that mZVI and biostimulation can be combined to achieve the efficient removal of various CAHs from contaminated groundwater sources.

Keywords: chlorinated aliphatic hydrocarbons, groundwater, field study, zero-valent iron, biostimulation

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Authors: Shima Fasahat

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This research is an experimental research which was done about microbial fuel cells in order to study them for electricity generating and wastewater treatment. These days, it is very important to find new, clean and sustainable ways for energy supplying. Because of this reason there are many researchers around the world who are studying about new and sustainable energies. There are different ways to produce these kind of energies like: solar cells, wind turbines, geothermal energy, fuel cells and many other ways. Fuel cells have different types one of these types is microbial fuel cell. In this research, an MFC was built in order to study how it can be used for electricity generating and wastewater treatment. The microbial fuel cell which was used in this research is a reactor that has two tanks with a catalyst solution. The chemical reaction in microbial fuel cells is a redox reaction. The microbial fuel cell in this research is a two chamber MFC. Anode chamber is an anaerobic one (ABR reactor) and the other chamber is a cathode chamber. Anode chamber consists of stabilized sludge which is the source of microorganisms that do redox reaction. The main microorganisms here are: Propionibacterium and Clostridium. The electrodes of anode chamber are graphite pages. Cathode chamber consists of graphite page electrodes and catalysts like: O₂, KMnO₄ and C₆N₆FeK₄. The membrane which separates the chambers is Nafion117. The reason of choosing this membrane is explained in the complete paper. The main goal of this research is to generate electricity and treating wastewater. It was found that when you use electron receptor compounds like: O_2, MnO₄, C₆N₆FeK₄ the velocity of electron receiving speeds up and in a less time more current will be achieved. It was found that the best compounds for this purpose are compounds which have iron in their chemical formula. It is also important to pay attention to the amount of nutrients which enters to bacteria chamber. By adding extra nutrients in some cases the result will be reverse.  By using ABR the amount of chemical oxidation demand reduces per day till it arrives to a stable amount.

Keywords: anaerobic baffled reactor, bioenergy, electrode, energy efficient, microbial fuel cell, renewable chemicals, sustainable

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Authors: Maria Altamirano, Alfonso Duran

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Biostimulation has recently become important in order to improve the stability and performance of the anaerobic digestion (AD) process. This strategy involves the addition of nutrients or supplements to improve the rate of degradation of a native microbial consortium. With the aim of biostimulate sytrophism between secondary fermenting bacteria and methanogenic archaea, improving metabolite degradation and efficient conversion to methane, the addition of conductive materials, mainly carbon based have been studied. This research seeks to highlight the effect that coconut biochar (CBC) has on the metanogenic conversion of the organic fraction of municipal solid waste (OFMSW), analyzing the surface chemistry properties that give biochar its capacity to serve as a redox mediator in the anaerobic digestion process. The biochar characterization techniques were electrical conductivity (EC) scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), Fourier Transform Infrared Transmission Spectroscopy (FTIR) and Cyclic Voltammetry (CV). Effect of coconut biochar addition was studied using Authomatic Methane Potential Test System (AMPTS II) applying a one-way variance analysis to determine the dose that leads to higher methane performance. The surface chemistry of the CBC could confer properties that enhance the AD process, such as the presence of alkaline and alkaline earth metals and their hydrophobicity that may be related to their buffering capacity and the adsorption of polar and non-polar compounds, such as NH4+ and CO2. It also has aromatic functional groups, just as quinones, whose potential as a redox mediator has been demonstrated and its morphology allows it to form an immobilizing matrix that favors a closer activity among the syntrophic microorganisms, which directly contributed in the oxidation of secondary metabolites and the final reduction to methane, whose yield is increased by 39% compared to controls, with a CBC dose of 1 g/L.

Keywords: anaerobic digestion, biochar, biostimulation, syntrophic metabolism

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Authors: Rupa Jeena, Pankaj Chetry, Pradeep Sarin

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The study of fundamental particles and the forces governing them has always remained an attractive field of theoretical study to pursue. With the advancement and development of new technologies and instruments, it is possible now to perform particle physics experiments on a large scale for the validation of theoretical predictions. These experiments are generally carried out in a highly intense beam environment. This, in turn, requires the development of a detector prototype possessing properties like radiation tolerance, thermal stability, and fast timing response. Semiconductors like Silicon, Germanium, Diamond, and Gallium Nitride (GaN) have been widely used for particle detection applications. Silicon and germanium being narrow bandgap semiconductors, require pre-cooling to suppress the effect of noise by thermally generated intrinsic charge carriers. The application of diamond in large-scale experiments is rare owing to its high cost of fabrication, while GaN is one of the most extensively explored potential candidates. But we are aiming to introduce another wide bandgap semiconductor in this active area of research by considering all the requirements. We have made an attempt by utilizing the wide bandgap of rutile Titanium dioxide (TiO2) and other properties to use it for particle detection purposes. The thermal evaporation-oxidation (in PID furnace) technique is used for the deposition of the film, and the Metal Semiconductor Metal (MSM) electrical contacts are made using Titanium+Gold (Ti+Au) (20/80nm). The characterization comprising X-Ray Diffraction (XRD), Atomic Force Microscopy (AFM), Ultraviolet (UV)-Visible spectroscopy, and Laser Raman Spectroscopy (LRS) has been performed on the film to get detailed information about surface morphology. On the other hand, electrical characterizations like Current Voltage (IV) measurement in dark and light and test with laser are performed to have a better understanding of the working of the detector prototype. All these preliminary tests of the detector will be presented.

Keywords: particle detector, rutile titanium dioxide, thermal evaporation, wide bandgap semiconductors

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Authors: Temesgen Oljira, Olugbenga Akindeji Okunlola, Akinade Shadrach Olatunji, Dereje Ayalew, Bekele A. Bedada, Tasin Godlove Bafon

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The Megele area gold-bearing Neoproterozoic rocks in the Western Ethiopian Shield has been under exploration for the last few decades. The geochemical and ore petrological characterization of the gold-bearing granite gneiss and associated quartz vein is crucial in understanding the gold's genesis. The present study concerns the ore petrological, geochemical, and stable O2 and S characterization of the gold-bearing granite gneiss and associated quartz vein. This area is known for its long history of placer gold mining. The presence of quartz veins of different generations and orientations, visible sulfide mineralization, and oxidation suggests that the Megele area is geologically fertile for mineralization. The Au and base metals analysis also indicate that Megele area rocks are characterized by Cu (2-22 ppm av. 7.83 ppm), Zn (2-53 ppm av. 29.33 ppm), Co (1-27 ppm av. 13.33 ppm), Ni (2-16 ppm av. 10 ppm), Pb (5-10 ppm av. 8.33 ppm), Au (1-5 ppb av. 2.11 ppb), Ag (0.5 ppm), As (5-12 ppm av. 7.83 ppm), Cd (0.5ppm), Li (0.5 ppm), Mo (1-4 ppm av. 1.6 ppm), Sc (5-13 ppm av. 9.3 ppm), and Tl (10 ppm). The oxygen isotope (δ18O) values of gold-bearing granite gneiss and associated quartz veins range from +8.6 to +11.5 ‰, suggesting the mixing of metamorphic water with magmatic water within the ore-forming fluid. The Sulfur isotope (δ34S) values of gold-bearing granite gneiss range from -1.92 to -0.45 ‰ (mean value of -1.13 ‰) indicating the narrow range of value. This suggests that the sulfides have been precipitated from the fluid system originating from a single source of the magmatic component under sulfur isotopic fractionation equilibrium condition. The tectonic setting of the host rocks, the occurrence of ore bodies, mineral assemblages of the host rocks and proposed ore-forming fluids of the Megele area gold prospects have similarities with features of orogenic gold deposit. The δ18O and δ34S isotopic values also suggested a metamorphic origin with the magmatic components. Thus, the Megele gold prospect could be related to an orogenic gold deposit related to metamorphism and associated intrusions.

Keywords: fluid source, gold mineralization, oxygen isotope, stable isotope, sulfur isotope

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Authors: Sarre Nzaba, Bulelwa Ntsendwana, Bekkie Mamba, Alex Kuvarega

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The discharge of azo dyes such as Brilliant black (BB) into the water bodies has carcinogenic and mutagenic effects on humankind and the ecosystem. Conventional water treatment techniques fail to degrade these dyes completely thereby posing more problems. Advanced oxidation processes (AOPs) are promising technologies in solving the problem. Anatase type nitrogen-platinum (N, Pt) co-doped TiO₂ photocatalysts were prepared by a modified sol-gel method using amine terminated polyamidoamine generation 1 (PG1) as a template and source of nitrogen. The resultant photocatalysts were characterized by X‐ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X‐ray photoelectron spectroscopy (XPS), UV‐Vis diffuse reflectance spectroscopy, photoluminescence spectroscopy (PL), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy (RS), thermal gravimetric analysis (TGA). The results showed that the calcination atmosphere played an important role in the morphology, crystal structure, spectral absorption, oxygen vacancy concentration, and visible light photocatalytic performance of the catalysts. Anatase phase particles ranging between 9- 20 nm were also confirmed by TEM, SEM, and analysis. The origin of the visible light photocatalytic activity was attributed to both the elemental N and Pd dopants and the existence of oxygen vacancies. Co-doping imparted a shift in the visible region of the solar spectrum. The visible light photocatalytic activity of the samples was investigated by monitoring the photocatalytic degradation of brilliant black dye. Co-doped TiO₂ showed greater photocatalytic brilliant black degradation efficiency compared to singly doped N-TiO₂ or Pd-TiO₂ under visible light irradiation. The highest reaction rate constant of 3.132 x 10-2 min⁻¹ was observed for N, Pd co-doped TiO₂ (2% Pd). The results demonstrated that the N, Pd co-doped TiO₂ (2% Pd) sample could completely degrade the dye in 3 h, while the commercial TiO₂ showed the lowest dye degradation efficiency (52.66%).

Keywords: brilliant black, Co-doped TiO₂, polyamidoamine generation 1 (PAMAM G1), photodegradation

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Authors: Engy Shokry, Giancarlo La Marca, Maria Luisa Della Bona

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Newborn screening for Congenital Adrenal Hyperplasia (CAH) relies on quantification of 17α-hydroxyprogesterone using enzyme immunoassays. These assays, in spite of being rapid, readily available and easy to perform, its reliability was found questionable due to lack of selectivity and specificity resulting in large number of false-positives, consequently family anxiety and associated hospitalization costs. To improve specificity of conventional 17α-hydroxyprogesterone screening which may experience false transient elevation in preterm, low birth weight or acutely ill neonates, steroid profiling by LC-MS/MS as a second-tier test was implemented. Unlike the previously applied LC-MS/MS methods, with the disadvantage of requiring a relatively high number of blood drops. Since newborn screening tests are increasing, it is necessary to minimize the sample volume requirement to make the maximum use of blood samples collected on filter paper. The proposed new method requires just one 3.2 mm dried blood spot (DBS) punch. Extraction was done using methanol: water: formic acid (90:10:0.1, v/v/v) containing deuterium labelled internal standards. Extracts were evaporated and reconstituted in 10 % acetone in water. Column switching strategy for on-line sample clean-up was applied to improve the chromatographic run. The first separative step retained the investigated steroids and passed through the majority of high molecular weight impurities. After the valve switching, the investigated steroids are back flushed from the POROS® column onto the analytical column and separated using gradient elution. Found quantitation limits were 5, 10 and 50 nmol/L for 17α-hydroxyprogesterone, androstenedione and cortisol respectively with mean recoveries of between 98.31-103.24 % and intra-/ inter-assay CV% < 10 % except at LLOQ. The method was validated using standard addition calibration and isotope dilution strategies. Reference ranges were determined by analysing samples from 896 infants of various ages at the time of sample collection. The method was also applied on patients with confirmed CAH. Our method represents an attractive combination of low sample volume requirement, minimal sample preparation time without derivatization and quick chromatography (5 min). The three steroid profile and the concentration ratios (17OHP + androstenedione/cortisol) allowed better screening outcomes of CAH reducing false positives, associated costs and anxiety.

Keywords: congenital adrenal hyperplasia (CAH), 17α-hydroxyprogesterone, androstenedione, cortisol, LC-MS/MS

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Authors: Z. Kolacinski, L. Szymanski. G. Raniszewski, D. Koza, L. Pietrzak

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Magnetic Bio-Nano-Fluid (BNF) can be composed of a buffer fluid such as plasma and magnetic nanoparticles such as iron, nickel, cobalt and their oxides. However iron is one of the best elements for magnetization by electromagnetic radiation. It can be used as a tool for medical diagnosis and treatment. Radio frequency (RF) radiation is able to heat iron nanoparticles due to magnetic hysteresis. Electromagnetic heating of iron nanoparticles and ferro-fluids BNF can be successfully used for non-invasive thermal ablation of cancer cells. Moreover iron atoms can be carried by carbon nanotubes (CNTs) if iron is used as catalyst for CNTs synthesis. Then CNTs became the iron containers and they screen the iron content against oxidation. We will present a method of CNTs addressing to the required cells. For thermal ablation of cancer cells we use radio frequencies for which the interaction with human body should be limited to minimum. Generally, the application of RF energy fields for medical treatment is justified by deep tissue penetration. The highly iron doped CNTs as the carriers creating magnetic fluid will be presented. An excessive catalyst injection method using electrical furnace and microwave plasma reactor will be presented. This way it is possible to grow the Fe filled CNTs on a moving surface in continuous synthesis process. This also allows producing uniform carpet of the Fe filled CNTs carriers. For the experimental work targeted to cell ablation we used RF generator to measure the increase in temperature for some samples like: solution of Fe2O3 in BNF which can be plasma-like buffer, solutions of pure iron of different concentrations in plasma-like buffer and in buffer used for a cell culture, solutions of carbon nanotubes (MWCNTs) of different concentrations in plasma-like buffer and in buffer used for a cell culture. Then the targeted therapies which can be effective if the carriers are able to distinguish the difference between cancerous and healthy cell’s physiology are considered. We have developed an approach based on ligand-receptor or antibody-antigen interactions for the case of colon cancer.

Keywords: cancer treatment, carbon nano tubes, drag delivery, hyperthermia, iron

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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

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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: Prangya Ranjan Rout, Puspendu Bhunia, Rajesh Roshan Dash

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In a developing country like India, providing reliable and affordable wastewater treatment facilities in rural areas is a huge challenge. With the aim of enhancing the nutrient removal from rural domestic wastewater while reducing the cost of treatment process, a novel, integrated treatment system consisting of a multistage bio-filter with drop aeration and a post positioned attached growth carbonaceous denitrifying-bioreactor was designed and developed in this work. The bio-filter was packed with ‘dolochar’, a sponge iron industry waste, as an adsorbent mainly for phosphate removal through physiochemical approach. The Denitrifying bio-reactor was packed with many waste organic solid substances (WOSS) as carbon sources and substrates for biomass attachment, mainly to remove nitrate in biological denitrification process. The performance of the modular system, treating real domestic wastewater was monitored for a period of about 60 days and the average removal efficiencies during the period were as follows: phosphate, 97.37%; nitrate, 85.91%, ammonia, 87.85%, with mean final effluent concentration of 0.73, 9.86, and 9.46 mg/L, respectively. The multistage bio-filter played an important role in ammonium oxidation and phosphate adsorption. The multilevel drop aeration with increasing oxygenation, and the special media used, consisting of certain oxides were likely beneficial for nitrification and phosphorus removal, respectively, whereas the nitrate was effectively reduced by biological denitrification in the carbonaceous bioreactor. This treatment system would allow multipurpose reuse of the final effluent. Moreover, the saturated dolochar can be used as nutrient suppliers in agricultural practices and the partially degraded carbonaceous substances can be subjected to composting, and subsequently used as an organic fertilizer. Thus, the system displays immense potential for treating domestic wastewater significantly decreasing the concentrations of nutrients and more importantly, facilitating the conversion of the waste materials into usable ones.

Keywords: nutrient removal, denitrifying bioreactor, multi-stage bio-filter, dolochar, waste organic solid substances

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Authors: A. T. Toci, M. V. B. Zanoni

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The advanced oxidation processes have been defined as destructive technologies treatment of wastewater. These involve the formation of powerful oxidizing agents (usually hydroxyl radical .OH) capable of reacting with organic compounds present in wastewater, transforming damaging substances in CO2 and H2O (mineralization) or other innocuous products. However, the photochemical degradation with singlet oxygen has been little explored as oxidative pathway for the treatment of effluents containing food colorants. The molecular oxygen is an effective suppressor of organic molecules in the triplet excited state. One of the possible results of the physical withdrawal is the formation of singlet oxygen. Studies with singlet oxygen (1O2) show an high reactivity of the excited state of the molecule with olefins, aromatic hydrocarbons and a number of other organic and inorganic compounds. Its reactivity is about 2500 times larger than the oxygen in the ground state. Thus, in this work, it was studied the degradation of some dyes used in food industry (tartrazine, sunset yellow, erythrosine and carmoisine) by singlet oxygen. The sensitizer used for generating the 1O2 was methylene blue, which has a quantum yield generation of 0.50. Samples were prepared in water at a concentration of 5 ppm and irradiated with a sunlight simulator (Newport brand, model no. 67005) by consecutive 8h. The absorption spectra of UV-Vis molecules were made each hour irradiation. The degradation kinetics for each dye was determined using the maximum length of each dye absorption. The analysis by UV-Vis revealed that the processes were very efficient for the colorants sunset yellow and carmoisine. Both presented degradation kinetics of order zero with degradation constants 0.416 and 0.104, respectively. In the case of sunset yellow degradation reached 53% after 7h irradiation, Demonstrating the process efficiency. The erithrosine presented during the period irradiated a oscillating degradation kinetics, which requires further study. In the other hand, tartrazine was stable in the presence of 1O2. The investigation of the dyes degradation products owned degradation by 1O2 are underway, the techniques used for this are MS and NMR. The results of this study will enable the application of the cleanest methods for the treatment of industrial effluents, as there are other non-toxic and polluting molecules to generate 1O2.

Keywords: food colourants, singlet oxygen, degradation, wastewater, oxidative

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Authors: Kyung Suk Cho, Heung Youl Kim

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The analysis of the petrologic characteristics and thermal properties of crushed aggregates for concrete such as granite, gneiss, dolomite, shale and andesite found that rock-forming minerals decided the thermal properties of the aggregates. The thermal expansion coefficients of aggregates containing lots of quartz increased rapidly at 573 degrees due to quartz transition. The mass of aggregate containing carbonate minerals decreased rapidly at 750 degrees due to decarboxylation, while its specific heat capacity increased relatively. The mass of aggregates containing hydrated silicate minerals decreased more significantly, and their specific heat capacities were greater when compared with aggregates containing feldspar or quartz. It is deduced that the hydroxyl group (OH) in hydrated silicate dissolved as its bond became loose at high temperatures. Aggregates containing mafic minerals turned red at high temperatures due to oxidation response. Moreover, the comparison of cooling methods showed that rapid cooling using water resulted in more reduction in aggregate mass than slow cooling at room temperatures. In order to observe the fire resistance performance of concrete composed of the identical but coarse aggregate, mass loss and compressive strength reduction factor at 200, 400, 600 and 800 degrees were measured. It was found from the analysis of granite and gneiss that the difference in thermal expansion coefficients between cement paste and aggregates caused by quartz transit at 573 degrees resulted in thermal stress inside the concrete and thus triggered concrete cracking. The ferromagnesian hydrated silicate in andesite and shale caused greater reduction in both initial stiffness and mass compared with other aggregates. However, the thermal expansion coefficient of andesite and shale was similar to that of cement paste. Since they were low in thermal conductivity and high in specific heat capacity, concrete cracking was relatively less severe. Being slow in heat transfer, they were judged to be materials of high heat capacity.

Keywords: crush-aggregates, fire resistance, thermal expansion, heat transfer

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Authors: Kruti Jaruriya

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Distribution of arsenic (As) and its compound and related toxicology are serious concerns. This is particularly so since millions worldwide are suffering from toxicity due to drinking of As-contaminated groundwater. The Bengal delta plain, formed by the Ganga– Padma–Meghna–Brahmaputra river basin, covering several districts of West Bengal, India and Bangladesh is considered as the worst As affected alluvial basin. However, some equally affected, if not more, areas are emerging in upper Brahmaputra plains. The present study was carried out to examine As contamination trends in the worst affected part of Assam, India. Arsenic (As) mobilization to the groundwater of Brahmaputra floodplains was investigated in Titabor, Jorhat District, located in the North Eastern part of India. The groundwater and the aquifer geochemistry were characterized. The groundwater is characterized by high dissolved Fe, Mn, and HCO-3 and low concentrations of NO-3 and SO2-4 indicating anoxic conditions prevailing in the groundwater. Fifty groundwater samples collected from shallow and deep tubewells of Titabor, Jorhat district (Assam) were examined. Along with total As, examination of concentration levels of other key parameters, viz., pH, EC, Fe, Mn , Mg2+, Ca2+, Na+, K+, PO43- , HCO-3 , NO3- ,Cl - and SO42- was also carried out. In respect to the permissible guideline of World Health Organization (WHO: As 0.01 ppm, Fe 1.0 ppm, and Mn 0.3 ppm for potable water), the range of As concentration in the groundwater varied from 0.014 to 0.604 mg/L with mean concentration 0.184 mg/L. The present study showed that out of the 50 groundwater samples,100%, 54%, and 42% were found contaminated with higher metal contents (for total As, Fe, and Mn, respectively). The results of hydrogeochemical study revealed that the reductive dissolution of MnOOH and FeOOH represents an important mechanism of arsenic release in the study area along with major cations playing an important role in leaching of As into the groundwater. Arsenic released by oxidation of pyrite, as water levels are drawn down and air enters the aquifer, contributes negligibly to the problem of As pollution. Identification of the mechanism of As release to groundwater helps to provide a framework to guide the placement of new water wells so that they will have acceptable concentrations of As.

Keywords: arsenic, assam, brahmaputra floodplain, groundwater, hydrogeochemistry

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Authors: Nivatha Elangovan, Lakshman Neelakantan, Murugaiyan Amirthalingam

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Magnesium and its alloys are widely used for various lightweight engineering and biomedical applications as they render high strength to low weight ratio and excellent corrosion resistance. These alloys possess good bio-compatibility and similar mechanical properties to natural bone. However, manufacturing magnesium alloy components by conventional formative and subtractive methods is challenging due to their poor castability, oxidation potential, and machinability. Therefore, efforts are made to produce complex-design containing magnesium alloy components by additive manufacturing (AM). Arc-wire directed energy deposition (AW-DED), also known as wire arc additive manufacturing (WAAM), is more attractive to produce large volume components with increased productivity than any other AM technique. In this research work, efforts were made to optimise the deposition parameters to build thick-walled (about 10 mm) AZ31 magnesium alloy components by a gas metal arc (GMA) based AW-DED process. By using controlled dip short-circuiting metal transfer in a GMA process, depositions were carried out without defects and spatter formation. Current and voltage waveforms were suitably modified to achieve stable metal transfer. Moreover, the droplet transfer behaviour was analysed using high-speed image analysis and correlated with arc energy. Optical and scanning electron microscopy analyses were carried out to correlate the influence of deposition parameters with the microstructural evolution during deposition. The investigation reveals that by carefully controlling the current-voltage waveform and droplet transfer behaviour, it is possible to stabilise equiaxed grain microstructures in the deposited AZ31 components. The printed component exhibited an improved mechanical property as equiaxed grains improve the ductility and enhance the toughness. The equiaxed grains in the component improved the corrosion-resistant behaviour of other conventionally manufactured components.

Keywords: arc wire directed energy deposition, AZ31 magnesium alloy, equiaxed grain, corrosion

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Authors: B. Donkova, M. Nedyalkova, D. Mehandjiev

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Sparingly soluble manganese oxalate is an appropriate precursor for the preparation of nanosized manganese oxides, which have a wide range of technological application. During the precipitation of manganese oxalate, three crystal forms could be obtained – α-MnC₂O₄.2H₂O (SG C2/c), γ-MnC₂O₄.2H₂O (SG P212121) and orthorhombic MnC₂O₄.3H₂O (SG Pcca). The thermolysis of α-MnC₂O₄.2H₂O has been extensively studied during the years, while the literature data for the other two forms has been quite scarce. The aim of the present communication is to highlight the influence of the initial crystal structure on the decomposition mechanism of these three forms, their magnetic properties, the structure of the anhydrous oxalates, as well as the nature of the obtained oxides. For the characterization of the samples XRD, SEM, DTA, TG, DSC, nitrogen adsorption, and in situ magnetic measurements were used. The dehydration proceeds in one step with α-MnC₂O₄.2H2O and γ-MnC₂O₄.2H₂O, and in three steps with MnC₂O₄.3H2O. The values of dehydration enthalpy are 97, 149 and 132 kJ/mol, respectively, and the last two were reported for the first time, best to our knowledge. The magnetic measurements show that at room temperature all samples are antiferomagnetic, however during the dehydration of α-MnC₂O₄.2H₂O the exchange interaction is preserved, for MnC₂O₄.3H₂O it changes to ferromagnetic above 35°C, and for γ-MnC₂O₄.2H₂O it changes twice from antiferomagnetic to ferromagnetic above 70°C. The experimental results for magnetic properties are in accordance with the computational results obtained with Wien2k code. The difference in the initial crystal structure of the forms used determines different changes in the specific surface area during dehydration and different extent of Mn(II) oxidation during decomposition in the air; both being highest at α-MnC₂O₄.2H₂O. The isothermal decomposition of the different oxalate forms shows that the type and physicochemical properties of the oxides, obtained at the same annealing temperature depend on the precursor used. Based on the results from the non-isothermal and isothermal experiments, and from different methods used for characterization of the sample, a comparison of the nature, mechanism and peculiarities of the thermolysis of the different crystal forms of manganese oxalate was made, which clearly reveals the influence of the initial crystal structure. Acknowledgment: 'Science and Education for Smart Growth', project BG05M2OP001-2.009-0028, COST Action MP1306 'Modern Tools for Spectroscopy on Advanced Materials', and project DCOST-01/18 (Bulgarian Science Fund).

Keywords: crystal structure, magnetic properties, manganese oxalate, thermal behavior

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Authors: Anupam Chanda

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Presently Packaging plays a significant role for drug discoveries. The process of selecting materials and the type of packaging also offers an opportunity for the Packaging scientist to look for biological delivery choices. Most injectable protein products were supplied in some sort of glass vial, prefilled syringe, cartridge. Those product having high Ph content there is a chance of “delamination “from inner surface of glass vial. With protein-based drugs, the biggest issue is the effect of packaging derivatives on the protein’s threedimensional and surface structure. These are any effects that relate to denaturation or aggregation of the protein due to oxidation or interactions from contaminants or impurities in the preparation. The potential for these effects needs to be carefully considered in choosing the container and the container closure system to avoid putting patients in jeopardy. Cause of Delamination : -Formulations with a high pH include phosphate and citrate buffers increase the risk of glass delamination. -High alkali content in glass could accelerate erosion. -High temperature during the vial-forming process increase the risk of glass delamination. -Terminal sterilization (irradiated at 20-40 kGy for 150 min) also is a risk factor for specific products(veterinary parenteral administration),could cause delamination. -High product-storage temperatures and long exposure times can increase the rate and severity of glass delamination. How to prevent Delamination -Treating the surface of the glass vials with materials, such as ammonium sulfate or siliconization can reduce the rate of glass erosion. -Consider alternative sterilization methods only in rare cases. -The correct specification for the glass to ensure its suitability for the pH of the product. -Use Cyclic olefin copolymer(COC)/Cyclic olefin Polymer(COP) Adsorption of protein and Solutions: Option#1 Coat with linear methoxylated polyglycerol and hyperbranchedmethoxylated polyglycerol. Option#2 Thehyperbranched non-methoxylated coating performed best. Option#3 Coat with hyperbranched polyglycerol Option#4 Right selection of Sterilization of glass vial/syringe.

Keywords: delamination of glass, ptrotien adoptions inside the glass surface, extractable & leachable solutions, injectable designs for new drugs

Procedia PDF Downloads 86

Authors: Amel Bouaziz, Seddik Khennouf, Mussa Abu Zarga, Shtayway Abdalla, Saliha Djidel, Assia Bentahar, Saliha Dahamna, Smain Amira

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The present study aimed to evaluate the hypotensive and the in vitro antioxidant activities of Crataegus azarolus L. (Rosaceae), a plant widely used as natural remedy for hypertension in folk medicine. The antioxidant potential of methanolic extract (ME)and its three fractions of Chloroform (CHE), ethyl acetate (EAE)and water (AqE) have been investigated using several assays, including the DPPH scavenging, ABTS scavenging, hydroxyl radical scavenging. Inhibition of lipid peroxidation was performed by the β-carotene bleaching assay, ferric thiocyanate method and thiobarburic acid method. Total phenolic and total flavonoid contents of the extracts were estimated using Folin-Chiocalteu reagent and AlCl3, respectively. EAE extract showed the highest polyphenolic and flavonoids contents (396,04±1.20 mg GAE/g of dry extract and 32,73 ± 0.03mg QE/g of dry extract) respectively. Similarly, this extract possessed the highest scavenging activity for DPPH radical (IC 50 = 0,006±0,0001mg /ml), ABTS radical (IC50=0.0035±0,0007 mg/ml) and hydroxyl radical(IC 50=0,283± 0.01 mg/ml). In addition, the EAE exhibited the highest antioxidant activity in the inhibition of linoleic acid/ß-carotene coupled oxidation (89,21%), lipid peroxidation in the ferric thiocyanate(FTC) method (90.13%), and thio-barbituric acid (TBA) method (74.23%). Intravenous administration of Me and EAE decreased mean arterial blood pressure, systolic and diastolic blood pressure in anesthetized rats dose-dependently, at the dose range of 0.4 to 12 mg/kg. The mean arterial blood pressure dropped by 27.58 and 39.37% for ME and EAE, respectively. In conclusion, The present study supported the significant potential to use C. azarolus by-products as a source of natural antioxidants and provides scientific justification for its traditional uses as cardio-protective and anti-hypertensive remedy.

Keywords: Crataegus azarolus, polyphenols, flavonoids, hypertension, antioxidant activity, free radicals, peroxidation

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Authors: Danish Laidin, Peter Gostomski, Aaron Marshall, Carlo Carere

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Groundwater contamination of nitrate (NO3-) is becoming more prevalent in regions of intensive and extensive agricultural activities. Household nitrate removal involves using ion exchange membranes and reverse osmosis (RO) systems, whereas industrial nitrate removal may use organic carbon substrates (e.g. methanol) for heterotrophic microbial denitrification. However, these approaches both require high capital investment and operating costs. In this study, denitrification was demonstrated using bio-electrochemical systems (BESs) inoculated from sediments and microbial enrichment cultures. The BES reactors were operated continuously as microbial electrolytic cells (MECs) with a poised potential of -0.7V and -1.1V vs Ag/AgCl. Three parallel MECs were inoculated using hydrogen-driven denitrifying enrichments, stream sediments, and biofilm harvested from a denitrifying biotrickling filter, respectively. These reactors were continuously operated for over a year as various operating conditions were investigated to determine the optimal conditions for electroactive denitrification. The mass loading rate of nitrate was varied between 10 – 70 mg NO3-/d, and the maximum observed nitrate removal rate was 22 mg NO3- /(cm2∙d) with a current of 2.1 mA. For volumetric load experiments, the dilution rate of 1 mM NO3- feed was varied between 0.01 – 0.1 hr-1 to achieve a nitrate loading rate similar to the mass loading rate experiments. Under these conditions, the maximum rate of denitrification observed was 15.8 mg NO3- /(cm2∙d) with a current of 1.7mA. Hydrogen (H2) was supplied intermittently to investigate the hydrogenotrophic potential of the denitrifying biofilm electrodes. H2 supplementation at 0.1 mL/min resulted in an increase of nitrate removal from 0.3 mg NO3- /(cm2∙d) to 3.4 mg NO3- /(cm2∙d) in the hydrogenotrophically subcultured reactor but had no impact on the reactors which exhibited direct electron transfer properties. Results from this study depict the denitrification performance of the immobilized biofilm electrodes, either by direct electron transfer or hydrogen-driven denitrification, and the contribution of the planktonic cells present in the growth medium. Other results will include the microbial community analysis via 16s rDNA amplicon sequencing, varying the effect of poising cathodic potential from 0.7V to 1.3V vs Ag/AgCl, investigating the potential of using in-situ electrochemically produced hydrogen for autotrophic denitrification and adjusting the conductivity of the feed solution to mimic groundwater conditions. These findings highlight the overall performance of sediment inoculated MECs in removing nitrate and will be used for the future development of sustainable solutions for the treatment of nitrate polluted groundwater.

Keywords: bio-electrochemical systems, groundwater, electroactive denitrification, microbial electrolytic cell

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Authors: Parikshit Gogo, N. N. Dutta

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The oxidative enzymes specially laccase (benzenediol: oxygen oxidoreductase, E.C.1.10.3.2) from bacteria, fungi and plants have been playing an important role in green technologies due to their specific advantageous properties. Laccase from different sources and in different forms was used as a biocatalyst in many oxidation and conjugation reactions starting from phenol to hydrocarbons. Tea polyphenols and its derivatives attract the scientific community because of their potential use as antioxidants in food, pharmaceutical and cosmetic industries. Conjugate of polyphenols emerged as a novel materials which shows better stability and antioxidant properties in applied fields. The conjugation reaction of catechin with poly (allylamine) has been studied using free, immobilized and cross-linked enzyme crystals (CLEC) of laccase from Trametes versicolor with particular emphasis on the effect of pertinent variables and kinetic aspects of the reaction. The stability and antioxidant property of the conjugated product was improved as compared to the unconjugated tea polyphenols. The reaction was studied in 11 different solvents in order to deduce the solvent effect through an attempt to correlate the initial reaction rate with solvent properties such as hydrophobicity (logP), water solubility (logSw), electron pair acceptance (ETN) and donation abilities (DNN), polarisibility and dielectric constant which exhibit reasonable correlations. The study revealed, in general that polar solvents favour the initial reaction rate. The kinetics of the conjugation reaction conformed to the so-called Ping-Pong-Bi-Bi mechanism with catechin inhibition. The stability as well as activity of the CLEC was better than the free enzymes and immobilized laccase for practical application. In case of immobilized laccase system marginal diffusional limitation could be inferred from the experimental data. The kinetic parameters estimated by non-linear regression analysis were found to be KmPAA(mM) = 0.75, 1.8967 and Kmcat (mM) = 11.769, 15.1816 for free and immobilized laccase respectively. An attempt has been made to assess the activity of the laccase for the conjugation reaction in relation to other reactions such as dimerisation of ferulic acids and develop a protocol to enhance polyphenol antioxidant activity.

Keywords: laccase, catechin, conjugation reaction, antioxidant properties

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Authors: O. Phewnil, S. Khowhit, W. Inkapatanakul, A. Boutson, K. Chunkao, O. Chueawong, T. Pattamapitoon, N. Chanwong, C. Nimpee

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The King’s Royally Initiated Laem Phak Bia Environmental Research and Development Project (“the Royal LERD Project”) is located in Laem Phak Bia Sub-District, Ban Laem District, Phetchaburi Province, Thailand. Phetchaburi municipal wastewater was treated with a simple technology by using aquatic plants, constructed wetland, oxidation ponds through a nature-by-nature process. The effluent from the Royal LERD Project was discharged into Laem Phak Bia muddy beach. The soil sediment samples were collected from two zones (200 and 600 meters from the coast of the beach), and tested for cation-exchange capacity (CEC), pH and organic matter and soil particles content. The marine water samples were also collected from the beach in wet and dry seasons and analyzed for its quality and compositions, including but not limited to, biochemical oxygen demand (BOD), dissolved oxygen (DO), suspended solids (SS), nutrients, heavy metals (As, Cd, Cr, Hg, and Pb), and phytoplankton at high and low tides. The soil texture was sandy loam with high concentration of calcium and magnesium which showed a property of base (pH 8). The marine water was qualified with the standard limits of coastal water quality. A dominant species was Coscinodiscus sp. It was found approximately 70.46% of total phytoplankton species in Meretrix casta gastrointestinal tract. The concentration of the heavy metals (As, Cd, Cr, Hg, Ni and Pb) in the tissues and water content of two species of hard clams indicated that heavy metals in Meretrix casta were higher than those in Meretrix meretrix. However, the heavy metals in both species were under the standard limits and safe for consumption. It can be concluded that nutrients in effluent from the wastewater treatment systems play important role in promoting the growth of phytoplankton and generating abundance of hard clams on muddy beach.

Keywords: wastewater, phytoplankton, hard clam (Meretrix spp.), muddy beach

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Authors: Tooba Aslam, Efthalia Chatzisymeon

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UV-assisted irradiation technologies are well-established for water and wastewater treatment. UVC treatments are widely used at large-scale, while UVA irradiation has more often been applied in combination with a catalyst (e.g. TiO₂ or FeSO₄) in smaller-scale systems. A technical issue of these systems is the formation of fouling on the quartz sleeves that houses the lamps. This fouling can prevent complete irradiation, therefore reducing the efficiency of the process. This paper investigates the effects of operational parameters, such as the type of wastewater, irradiation source, H₂O₂ addition, and water pH on fouling formation and, ultimately, the treatment of municipal wastewater. Batch experiments have been performed at lab-scale while monitoring water quality parameters including: COD, TS, TSS, TDS, temperature, pH, hardness, alkalinity, turbidity, TOC, UV transmission, UV₂₅₄ absorbance, and metal concentrations. The residence time of the wastewater in the reactor was 5 days in order to observe any fouling formation on the quartz surface. Over this period, it was observed that chemical oxygen demand (COD) decreased by 30% and 59% during photolysis (Ultraviolet A) and photo-catalysis (UVA/Fe/H₂O₂), respectively. Higher fouling formation was observed with iron-rich and phosphorous-rich wastewater. The highest rate of fouling was developed with phosphorous-rich wastewater, followed by the iron-rich wastewater. Photo-catalysis (UVA/Fe/H₂O₂) had better removal efficiency than photolysis (UVA). This was attributed to the Photo-Fenton reaction, which was initiated under these operational conditions. Scanning electron microscope (SEM) measurements of fouling formed on the quartz sleeves showed that particles vary in size, shape, and structure; some have more distinct structures and are generally larger and have less compact structure than the others. Energy-dispersive X-ray spectroscopy (EDX) results showed that the major metals present in the fouling cake were iron, phosphorous, and calcium. In conclusion, iron-rich wastewaters are more suitable for UV-assisted treatment since fouling formation on quartz sleeves can be minimized by the formation of oxidizing agents during treatment, such as hydroxyl radicals.

Keywords: advanced oxidation processes, photo-fenton treatment, photo-catalysis, wastewater treatment

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Authors: Janneth Gonzalez, Andres Pinzon Velasco, Maria Angarita, Nicolas Mendoza

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Astrocytes play an important role in various processes in the brain, including pathological conditions such as neurodegenerative diseases. Recent studies have shown that the increase in saturated fatty acids such as palmitic acid (PA) triggers pro-inflammatory pathways in the brain. The use of synthetic neurosteroids such as tibolone has demonstrated neuro-protective mechanisms. However, there are few studies on the neuro-protective mechanisms of tibolone, especially at the systemic (omic) level. In this study, we performed the integration of multi-omic data (transcriptome and proteome) into a human astrocyte genomic scale metabolic model to study the astrocytic response during palmitate treatment. We evaluated metabolic fluxes in three scenarios (healthy, induced inflammation by PA, and tibolone treatment under PA inflammation). We also use control theory to identify those reactions that control the astrocytic system. Our results suggest that PA generates a modulation of central and secondary metabolism, showing a change in energy source use through inhibition of folate cycle and fatty acid β-oxidation and upregulation of ketone bodies formation.We found 25 metabolic switches under PA-mediated cellular regulation, 9 of which were critical only in the inflammatory scenario but not in the protective tibolone one. Within these reactions, inhibitory, total, and directional coupling profiles were key findings, playing a fundamental role in the (de)regulation in metabolic pathways that increase neurotoxicity and represent potential treatment targets. Finally, this study framework facilitates the understanding of metabolic regulation strategies, andit can be used for in silico exploring the mechanisms of astrocytic cell regulation, directing a more complex future experimental work in neurodegenerative diseases.

Keywords: astrocytes, data integration, palmitic acid, computational model, multi-omics, control theory

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Authors: Luís R. Silva, Catarina Bento, Ana C. Gonçalves, Fábio Jesus, Branca M. Silva

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Nowadays, the general population is more and more concerned about nutrition and the health implications of an unbalanced diet. Current knowledge regarding the health benefits and antioxidant properties of certain foods such as fruits and vegetables has gained the interest of both the general public and scientific community. Peach (Prunus persica (L.) Batsch) is one of the most consumed fruits worldwide, with low sugar contents and a broad range of nutrients essential to the normal functioning of the body. Six different peach cultivars from the Fundão region in Portugal were evaluated regarding their phenolic composition by LC-DAD and biological activity. The prepared extracts’ capacity to scavenge free-radicals was tested through the stable free radical DPPH• and nitric oxide (•NO). Additionally, antidiabetic potential and protective effects against peroxyl radical (ROO•) induced damage to erythrocytes were also tested. LC-DAD analysis allowed the identification of 17 phenolic compounds, among which 5-O-caffeoylquinic acids and 3-O-caffeoylquinic acids are pointed out as the most abundant. Regarding the antioxidant activity, all cultivars displayed concentration-dependent free-radical scavenging activity against both nitrogen species and DPPH•. In respect to α-glucosidase inhibitory activity, Royal Magister and Royal Glory presented the highest inhibitory activity (IC50 = 11.7 ± 1.4 and 17.1 ± 1.7 μg/mL, respectively), nevertheless all six cultivars presented higher activity than the control acarbose. As for the protective effect of Royal Lu extract on the oxidative damage induced in erythrocytes by ROO•, the results were quite promising showing inhibition IC50 values of 110.0 ± 4.5 μg/mL and 83.8 ± 6.5 μg/mL for hemolysis and hemoglobin oxidation, respectively. The demonstrated activity is of course associated to the peaches’ phenolic profile, rich in phenolic acids and flavonoids with high hydrogen donating capacity. These compounds have great industrial interest for the manufacturing of natural products. The following step would naturally be the extraction and isolation from the plant tissues and large-scale production through biotechnology techniques.

Keywords: antioxidants, functional food, phenolic compounds, peach

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