Search results for: membrane synthesis

Authors: Chang-Hui Shen, Paulina Konarzewska

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Cell homeostasis is regulated by vacuolar activity and it has been shown that lipid composition of the vacuole plays an important role in vacuolar function. The major phosphoinositide species present in the vacuolar membrane include phosphatidylinositol 3,5-biphosphate (PI(3,5)P₂) which is generated from PI(3)P controlled by Fab1p. Deletion of FAB1 gene reduce the synthesis of PI(3,5)P₂ and thus result in enlarged or fragmented vacuoles, with neutral vacuolar pH due to reduced vacuolar H⁺-ATPase activity. These mutants also exhibited poor growth at high extracellular pH and in the presence of CaCl₂. Conversely, VPS34 regulates the synthesis of PI(3)P from phosphatidylinositol (PI), and the lack of Vps34p results in the reduction of vacuolar activity. Although the cellular observations are clear, it is still unknown about the molecular mechanism between the phospholipid biosynthesis pathway and vacuolar activity. Since both VPS34 and FAB1 are important in vacuolar activity, we hypothesize that the molecular mechanism of vacuolar function might be regulated by the transcriptional regulators of phospholipid biosynthesis. In this study, we study the role of the major phospholipid biosynthesis transcription factor, INO2, in the regulation of vacuolar activity. We first performed qRT-PCR to examine the effect of Ino2p on the expression of VPS34 and FAB1. Our results showed that VPS34 was upregulated in the presence of inositol for both WT and ino2Δ cells. However, FAB1 was only upregulated significantly in ino2Δ cells. This indicated that Ino2p might be the negative regulator for FAB1 expression. Next, growth sensitivity experiment showed that WT, vma3Δ, and ino2Δ grew well in growth medium buffered to pH 5.5 containing 10 mM CaCl₂. As cells were switched to growth medium buffered to pH 7 containing CaCl₂ WT, ino2Δ and opi1Δ showed growth reduction, whereas vma3Δ was completely nonviable. As the concentration of CaCl₂ was increased to 60 mM, ino2Δ cells showed moderate growth reduction compared to WT. This result suggests that ino2Δ cells have better vacuolar activity. Microscopic analysis and vacuolar acidification were employed to further elucidate the importance of INO2 in vacuolar homeostasis. Analysis of vacuolar morphology indicated that WT and vma3Δ cells displayed vacuoles that occupied a small area of the cell when grown in media buffered to pH 5.5. Whereas, ino2Δ displayed fragmented vacuoles. On the other hand, all strains grown in media buffered to pH 7, exhibited enlarged vacuoles that occupied most of the cell’s surface. This indicated that the presence of INO2 may play negative effect in vacuolar morphology when cells are grown in media buffered to pH 5.5. Furthermore, vacuolar acidification assay showed that only vma3Δ cells displayed notably less acidic vacuoles as cells were grown in media buffered to pH 5.5 and pH 7. Whereas, ino2Δ cells displayed more acidic pH compared to WT at pH7. Taken together, our results demonstrated the molecular mechanism of the vacuolar activity regulated by the phospholipid biosynthesis transcription factors Ino2p. Ino2p negatively regulates vacuolar activity through the expression of FAB1.

Keywords: vacuole, phospholipid, homeostasis, Ino2p, FAB1

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Authors: F. Karim

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In this paper, triangular lattice index-guiding photonic crystal fibers (PCFs) are synthesized to compensate the chromatic dispersion of a single mode fiber (SMF-28) for an 80 km optical link operating at 1.55 µm, by using the directed tabu search algorithm. Hole-to-hole distance, circular air-hole diameter, solid-core diameter, ring number and PCF length parameters are optimized for this purpose. Three Synthesized PCFs with different physical parameters are compared in terms of their objective functions values, residual dispersions and compensation ratios.

Keywords: triangular lattice index-guiding photonic crystal fiber, dispersion compensation, directed tabu search, synthesis

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Authors: Pinki Sharma, Himanshu Joshi

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Distillery spentwash contains high chemical oxygen demand (COD), biological oxygen demand (BOD), color, total dissolved solids (TDS) and other contaminants even after biological treatment. The effluent can’t be discharged as such in the surface water bodies or land without further treatment. Reverse osmosis (RO) treatment plants have been installed in many of the distilleries at tertiary level. But at most of the places these plants are not properly working due to high concentration of organic matter and other contaminants in biologically treated spentwash. To make the membrane treatment proven and reliable technology, proper pre-treatment is mandatory. In the present study, ultra-filtration (UF) as pre-treatment of RO at tertiary stage was performed. Operating parameters namely initial pH (pHo: 2–10), trans-membrane pressure (TMP: 4-20 bars) and temperature (T: 15- 43°C) used for conducting experiments with UF system. Experiments were optimized at different operating parameters in terms of COD, color, TDS and TOC removal by using response surface methodology (RSM) with central composite design. The results showed that removal of COD, color and TDS by 62%, 93.5% and 75.5%, with UF, respectively at optimized conditions with increased permeate flux from 17.5 l/m2/h (RO) to 38 l/m2/h (UF-RO). The performance of the RO system was greatly improved both in term of pollutant removal as well as water recovery.

Keywords: bio-digested distillery spentwash, reverse osmosis, response surface methodology, ultra-filtration

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Authors: A. Zarenezhad, A. Esfandiari, E. Zarenezhad, M. Mardkhoshnood

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The aim of this study was to investigate the ultra-structure of the photoreceptor layer of male rats under the effect of methanol intoxication and protective effect of silymarin against the methanol toxicity. Fifteen adult male rats were divided into three groups: Control group, Experimental group I (received 4g/kg methanol by intraperitoneal injection for five days), Experimental group II (received 4 g/kg methanol by intraperitoneal injection for five days and received 250 mg/kg silymarin orally for three months). At the end of the experiment, the eyes were removed; retina was separated near the optic disc and studied by transmission electron microscope. Results showed that the retina in the experimental group I exhibited loss of outer segments and disorganization in inner segment. Increased extra cellular space, disappearance of outer limiting membrane and pyknotic nuclei were seen in this group. But normal outer segment, organized inner segment and normal outer limiting membrane were obvious after treatment with silymarin in experimental group II. These findings show that methanol causes damage in the photoreceptor layer of the rat retina and silymarin can protect the damage to retina against the methanol intoxication.

Keywords: ultra-structure, photoreceptor layer, methanol intoxication, silymarin, rat

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Authors: K. Uyanga, W. Daoud

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Hydrogels have attracted much academic and industrial attention due to their unique properties and potential biomedical and non-biomedical applications. Limitations on extending their applications have resulted from the synthesis of hydrogels using toxic materials and complex irreproducible processing techniques. In order to promote environmental sustainability, hydrogel efficiency, and wider application, this study focused on the synthesis of composite hydrogels matrices from an edible non-toxic crosslinker-citric acid (CA) using a simple low energy processing method based on carboxymethyl cellulose (CMC) and chitosan (CSN) natural polymers. Composite hydrogels were developed by chemical crosslinking. The results demonstrated that CMC:2CSN:CA exhibited good performance properties and super-absorbency 21× its original weight. This makes it promising for biomedical applications such as chronic wound healing and regeneration, next generation skin substitute, in situ bone regeneration and cell delivery. On the other hand, CMC:CSN:CA exhibited durable well-structured internal network with minimum swelling degrees, water absorbency, excellent gel fraction, and infra-red reflectance. These properties make it a suitable composite hydrogel matrix for warming effect and controlled and efficient release of loaded materials. CMC:2CSN:CA and CMC:CSN:CA composite hydrogels developed also exhibited excellent chemical, morphological, and thermal properties.

Keywords: citric acid, fumaric acid, tartaric acid, zinc nitrate hexahydrate

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Authors: M. Venegas, M. De Vega, N. García-Hernando

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Absorption cooling chillers have received growing attention over the past few decades as they allow the use of low-grade heat to produce the cooling effect. The combination of this technology with solar thermal energy in the summer period can reduce the electricity consumption peak due to air-conditioning. One of the main components, the absorber, is designed for simultaneous heat and mass transfer. Usually, shell and tubes heat exchangers are used, which are large and heavy. Cooling water from a cooling tower is conventionally used to extract the heat released during the absorption and condensation processes. These are clear inconvenient for the generalization of the absorption technology use, limiting its benefits in the contribution to the reduction in CO2 emissions, particularly for the H2O-LiBr solution which can work with low heat temperature sources as provided by solar panels. In the present work a promising new technology is under study, consisting in the use of membrane contactors in adiabatic microchannel mass exchangers. The configuration here proposed consists in one or several modules (depending on the cooling capacity of the chiller) that contain two vapour channels, separated from the solution by adjacent microporous membranes. The solution is confined in rectangular microchannels. A plastic or synthetic wall separates the solution channels between them. The solution entering the absorber is previously subcooled using ambient air. In this way, the need for a cooling tower is avoided. A model of the configuration proposed is developed based on mass and energy balances and some correlations were selected to predict the heat and mass transfer coefficients. The concentration and temperatures along the channels cannot be explicitly determined from the set of equations obtained. For this reason, the equations were implemented in a computer code using Engineering Equation Solver software, EES™. With the aim of minimizing the absorber volume to reduce the size of absorption cooling chillers, the ratio between the cooling power of the chiller and the absorber volume (R) is calculated. Its variation is shown along the solution channels, allowing its optimization for selected operating conditions. For the case considered the solution channel length is recommended to be lower than 3 cm. Maximum values of R obtained in this work are higher than the ones found in optimized horizontal falling film absorbers using the same solution. Results obtained also show the variation of R and the chiller efficiency (COP) for different ambient temperatures and desorption temperatures typically obtained using flat plate solar collectors. The configuration proposed of adiabatic membrane-based absorber using ambient air to subcool the solution is a good technology to reduce the size of the absorption chillers, allowing the use of low temperature solar heat and avoiding the need for cooling towers.

Keywords: adiabatic absorption, air-cooled, membrane, solar thermal energy

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Authors: Tanghourte Mohamed, Ouassou Nazih, El Mesky Mohammed, Znini Mohamed, Mabrouk El Houssine

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In the present study, a distinct organic inhibitor, namely 2,2'-(piperazine-1,4-diyl)bis(N-(4-bromophenyl)acetamide) (PBRA), was synthesized and characterized using ¹H, ¹³C NMR, and IR spectroscopy. Subsequently, the inhibition effect of PBRA on the corrosion of carbon steel in 1 M HCl was studied using electrochemical measurements such as potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS). The results showed that the inhibition efficiency increased with concentration, reaching 87% at 10-³M. Furthermore, PBRA remained effective at temperatures ranging from 298 to 328 K. The adsorption of the inhibitor onto carbon steel was well described by the Langmuir adsorption isotherm. Additionally, a correlation between the molecular structure and quantum chemistry indices was established using density functional theory (DFT).

Keywords: synthesis, corrosion, inhibition, piperazine, efficacy, isotherm, acetamide

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Authors: N. Naga Subrahmanyeswara Rao, Parag Arvind Deshpande

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Understanding nucleotide synthesis reaction of any organism is beneficial to know the growth of it as in Mycobacterium tuberculosis to design anti TB drug. One of the reactions of de novo pathway which takes place in all organisms was considered. The reaction takes places between phosphoribosyl pyrophosphate and orotate catalyzed by orotate phosphoribosyl transferase and divalent metal ion gives orotdine monophosphate, a nucleotide. All the reaction steps of three experimentally proposed mechanisms for this reaction were considered to develop kinetic rate expression. The model was validated using the data for four organisms. This model could successfully describe the kinetics for the reported data. The developed model can serve as a reliable model to describe the kinetics in new organisms without the need of mechanistic determination. So an organism-independent model was developed.

Keywords: mechanism, nucleotide, organism, tuberculosis

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Authors: Novutry Siregar, Afdal, Emilzon Taslim

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Hyaline Membrane Disease (HMD) is the main cause of respiratory failure in preterm neonates caused by surfactant deficiency. Nasal Continuous Positive Airway Pressure (NCPAP) is the therapy for HMD. The success of therapy is determined by gestational age, birth weight, HMD grade, time of NCAP administration, and time of breathing frequency recovery. The aim of this research is to identify the predictive factor of NCPAP therapy success in preterm neonates with HMD. This study used a cross-sectional design by using medical records of patients who were treated in the Perinatology of the Pediatric Department of Dr. M. Djamil Padang Central Hospital from January 2015 to December 2017. The samples were eighty-two neonates that were selected by using the total sampling technique. Data analysis was done by using the Chi-Square Test and the Multiple Logistic Regression Prediction Model. The results showed the success rate of NCPAP therapy reached 53.7%. Birth weight (p = 0.048, OR = 3.34 95% CI 1.01-11.07), HMD grade I (p = 0.018, OR = 4.95 CI 95% 1.31-18.68), HMD grade II (p = 0.044, OR = 5.52 95% CI 1.04-29.15), and time of breathing frequency recovery (p = 0,000, OR = 13.50 95% CI 3.58-50, 83) are the predictive factors of NCPAP therapy success in preterm neonates with HMD. The most significant predictive factor is the time of breathing frequency recovery.

Keywords: predictive factors, the success of therapy, NCPAP, preterm neonates, HMD

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Authors: Priyansha Sharma, Sibani Mund, Sivakumar Vaidyanathan

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Solid-state synthesis methods were used for the synthesis of pure red emissive Li¬3BaSrxCa(1-x)Eu2.7Gd0.3(MoO4)8 (x = 0.0 to 1.0) phosphors, XRD, SEM, and FTIR spectra were used to characterize the materials, and their optical properties were thoroughly investigated. PL studies were examined at different excitations 230 nm, 275nm, 465nm, and 395 nm. All the spectra show similar emissions with the highest transition at 616 nm due to ED transition. The given phosphor Li¬3BaSr0.25Ca0.75Eu2.7Gd0.3(MoO4)8 shows the highest intensity and is thus chosen for the temperature-dependent and Quantum yield study. According to the PL investigation, the phosphor-containing Eu3+ emits red light due to the (5D0 7F2) transition. The excitation analysis shows that all of the Eu3+ activated phosphors exhibited broad absorption due to the charge transfer band, O2-Mo6+, O2-Eu3+ transition, as well as narrow absorption bands related to the Eu3+ ion's 4f-4f electronic transition. Excitation spectra show Charge transfer band at 275 nm shows the highest intensity. The primary band in the spectra refers to Eu3+ ions occupying the lattice's non-centrosymmetric location. All of the compositions are monoclinic crystal structures with space group C2/c and match with reference powder patterns. The thermal stability of the 3BaSr0.25Ca0.75Eu2.7Gd0.3(MoO4)8 phosphor was investigated at (300 k- 500 K) as well as at low temperature from (20 K to 275 K) to be utilized for red and white LED fabrication. The Decay Lifetime of all the phosphor was measured. The best phosphor was used for White and Red LED fabrication.

Keywords: PL, phosphor, quantum yield, white LED

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Authors: Juan C. Duran-Alvarez, Daniel Mejia, Rodolfo Zanella

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Heterogeneous photocatalysis is a promising method to achieve the complete degradation and mineralization of organic pollutants in water via their exhaustive oxidation. In order to take this advanced oxidation process towards sustainability, it is necessary to reduce the energy consumption, referred as the light sources and the post-treatment operations. For this, the synthesis of new nanostructures of low band gap semiconductors in the form of thin films is in continuous development. In this work, thin films of the low band gap semiconductor bismuth oxyiodide (BiOI) were synthesized via the Successive Ionic Layer Adsorption and Reaction (SILAR) method. For this, Bi(NO3)3 and KI solutions were prepared, and glass supports were immersed in each solution under strict rate and time immersion conditions. Synthesis was performed at room temperature and a washing step was set prior to each immersion. Thin films with an average thickness below 100 nm were obtained upon a cycle of 30 immersions, as determined by AFM and profilometry measurements. Cubic BiOI nanocrystals with average size of 17 nm and a high orientation to the 001 plane were observed by XRD. In order to optimize the synthesis method, several Bi/I ratios were tested, namely 1/1, 1/5, 1/10, 1/20 and 1/50. The highest crystallinity of the BiOI films was observed when the 1/5 ratio was used in the synthesis. Non-stoichiometric conditions also resulted in the highest uniformity of the thin layers. PVP was used as an additive to improve the adherence of the BiOI thin films to the support. The addition of 0.1 mg/mL of PVP during the washing step resulted in the highest adherence of the thin films. In photocatalysis tests, degradation rate of the antibiotic ciprofloxacin as high as 75% was achieved using visible light (380 to 700 nm) irradiation for 5 h in batch tests. Mineralization of the antibiotic was also observed, although in a lower extent; ~ 30% of the total organic carbon was removed upon 5 h of visible light irradiation. Some ciprofloxacin by-products were identified throughout the reaction; and some of these molecules displayed residual antibiotic activity. In conclusion, it is possible to obtain highly oriented BiOI thin films under ambient conditions via the SILAR method. Non-stoichiometric conditions using PVP additive are necessary to increase the crystallinity and adherence of the films, which are photocatalytically active to remove recalcitrant organic pollutants under visible light irradiation.

Keywords: bismuth oxyhalides, photocatalysis, thin films, water treatment

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Authors: Nidhi Chadha, A. K. Tiwari, Marilyn D. Milton, Anil K. Mishra

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Translocator protein (18 kDa) TSPO is highly expressed during microglia activation in neuroinflammation. Although a number of PET ligands have been developed for the visualization of activated microglia, one of the advantageous approaches is to develop potential optical imaging (OI) probe. Our study involves computational screening, synthesis and evaluation of TSPO ligand through various imaging modalities namely PET/SPECT/Optical. The initial computational screening involves pharmacophore modeling from the library designing having oxo-benzooxazol-3-yl-N-phenyl-acetamide groups and synthesis for visualization of efficacy of these compounds as multimodal imaging probes. Structure modeling of monomer, Ala147Thr mutated, parallel and anti-parallel TSPO dimers was performed and docking analysis was performed for distinct binding sites. Computational analysis showed pattern of variable binding profile of known diagnostic ligands and NBMP via interactions with conserved residues along with TSPO’s natural polymorphism of Ala147→Thr, which showed alteration in the binding affinity due to considerable changes in tertiary structure. Preliminary in vitro binding studies shows binding affinity in the range of 1-5 nm and selectivity was also certified by blocking studies. In summary, this skeleton was found to be potential probe for TSPO imaging due to ease in synthesis, appropriate lipophilicity and reach to specific region of brain.

Keywords: TSPO, molecular modeling, imaging, docking

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Authors: Chii-Dong Ho, Jian-Har Chen

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The decline in permeate flux across membrane modules is attributed to the increase in temperature polarization resistance in flat-plate Direct Contact Membrane Distillation (DCMD) modules for pure water productivity. Researchers have discovered that this effect can be diminished by embedding turbulence promoters, which augment turbulence intensity at the cost of increased power consumption, thereby improving vapor permeate flux. The device performance of DCMD modules for permeate flux was further enhanced by shrinking the hydraulic diameters of inserted S-ribs carbon-fiber promoters as well as considering the energy consumption increment. The mass-balance formulation, based on the resistance-in-series model by energy conservation in one-dimensional governing equations, was developed theoretically and conducted experimentally on a flat-plate polytetrafluoroethylene/polypropylene (PTFE/PP) membrane module to predict permeate flux and temperature distributions. The ratio of permeate flux enhancement to energy consumption increment, as referred to an assessment on economic viewpoint and technical feasibilities, was calculated to determine the suitable design parameters for DCMD operations with the insertion of S-ribs carbon-fiber turbulence promoters. An economic analysis was also performed, weighing both permeate flux improvement and energy consumption increment on modules with promoter-filled channels by different array configurations and various hydraulic diameters of turbulence promoters. Results showed that the ratio of permeate flux improvement to energy consumption increment in descending hydraulic-diameter modules is higher than in uniform hydraulic-diameter modules. The fabrication details of the DCMD module filaments implementing the S-ribs carbon-fiber filaments and the schematic configuration of the flat-plate DCMD experimental setup with presenting acrylic plates as external walls were demonstrated in the present study. The S-ribs carbon fibers perform as turbulence promoters incorporated into the artificial hot saline feed stream, which was prepared by adding inorganic salts (NaCl) to distilled water. Theoretical predictions and experimental results exhibited a great accomplishment to considerably achieve permeate flux enhancement, such as the new design of the DCMD module with inserting S-ribs carbon-fiber promoters. Additionally, the Nusselt number for the water vapor transferring membrane module with inserted S-ribs carbon-fiber promoters was generalized into a simplified expression to predict the heat transfer coefficient and permeate flux as well.

Keywords: permeate flux, Nusselt number, DCMD module, temperature polarization, hydraulic diameters

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Authors: Beata Pospiech

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Separation of metal ions from aqueous solutions is important as well as difficult process in hydrometallurgical technology. This process is necessary for obtaining of clean metals. Solvent extraction and membrane processes are well known as separation methods. Recently, ionic liquids (ILs) are very often applied and studied as extractants and carriers of metal ions from aqueous solutions due to their good extractability properties for various metals. This work discusses a method to separate copper(II) and iron(III) from hydrochloric acid solutions by solvent extraction and transport across polymer inclusion membranes (PIM) with the selected ionic liquids as extractants/ion carriers. Cyphos IL 101 (trihexyl(tetradecyl)phosphonium chloride), Cyphos IL 104 (trihexyl(tetradecyl)phosphonium bis(2,4,4 trimethylpentyl)phosphi-nate), trioctylmethylammonium thiosalicylate [A336][TS] and trihexyl(tetradecyl)phosphonium thiosalicylate [PR4][TS] were used for the investigations. Effect of different parameters such as hydrochloric acid concentration in aqueous phase on iron(III) and copper(II) extraction has been investigated. Cellulose triacetate membranes with the selected ionic liquids as carriers have been prepared and applied for transport of iron(IIII) and copper(II) from hydrochloric acid solutions.

Keywords: copper, iron, ionic liquids, solvent extraction

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Authors: Yemane Tadesse Gebreslassie, Fisseha Guesh Gebremeskel

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Nanotechnology has made remarkable advancements in recent years, revolutionizing various scientific fields, industries, and research institutions through the utilization of metal and metal oxide nanoparticles. Among these nanoparticles, copper oxide nanoparticles (CuO NPs) have garnered significant attention due to their versatile properties and wide-range applications, particularly, as effective antimicrobial and anticancer agents. CuO NPs can be synthesized using different methods, including physical, chemical, and biological approaches. However, conventional chemical and physical approaches are expensive, resource-intensive, and involve the use of hazardous chemicals, which can pose risks to human health and the environment. In contrast, biological synthesis provides a sustainable and cost-effective alternative by eliminating chemical pollutants and allowing for the production of CuO NPs of tailored sizes and shapes. This comprehensive review focused on the green synthesis of CuO NPs using various biological resources, such as plants, microorganisms, and other biological derivatives. Current knowledge and recent trends in green synthesis methods for CuO NPs are discussed, with a specific emphasis on their biomedical applications, particularly in combating cancer and microbial infections. This review highlights the significant potential of CuO NPs in addressing these diseases. By capitalizing on the advantages of biological synthesis, such as environmental safety and the ability to customize nanoparticle characteristics, CuO NPs have emerged as promising therapeutic agents for a wide range of conditions. This review presents compelling findings, demonstrating the remarkable achievements of biologically synthesized CuO NPs as therapeutic agents. Their unique properties and mechanisms enable effective combating against cancer cells and various harmful microbial infections. CuO NPs exhibit potent anticancer activity through diverse mechanisms, including induction of apoptosis, inhibition of angiogenesis, and modulation of signaling pathways. Additionally, their antimicrobial activity manifests through various mechanisms, such as disrupting microbial membranes, generating reactive oxygen species, and interfering with microbial enzymes. This review offers valuable insights into the substantial potential of biologically synthesized CuO NPs as an alternative approach for future therapeutic interventions against cancer and microbial infections.

Keywords: copper oxide nanoparticles, green synthesis, nanotechnology, microbial infection

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Authors: Akintayo Emmanuel Temitope, Akintayo Cecilia Olufunke, Ziegler Thomas

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Bio-polyols are important components in polyurethane industries. The preliminary studies into the synthesis of bio-polyol products (epoxy-polyol and epoxyl-polyurethanes) from Jatropha curcas were investigated. The reactions were followed by both infrared and nuclear magnetic resonance. Physico-chemical characterisation of the samples for iodine value (IV), acid value (AV), saponification value (SV) and hydroxyl value (HV) were carried out. Thermal transitions of the products were studied by heating 5 mg of the sample from 20ºC to 800ºC and then cooling down to -500ºC on a differential scanning calorimeter (DSC). The preparation of epoxylpolyol and polyurethane from Jatropha curcas oil was smooth and efficient. Results of film and solubility properties revealed that coatings of Jatropha curcas epoxy-polyurethanes performed better with increased loading of toluylene 2, 4-diisocyanate (TDI) up to 2 wt% while their solvent resistance decreased beyond a TDI loading of 1.2 wt%. DSC analysis shows the epoxy-polyurethane to be less stable compared to the epoxy-polyol.

Keywords: synthesis, epoxy-polyol, epoxy-polyurethane, jatropha curcas oil

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Authors: Agnieszka Fryźlewicz, Jowita Kras, Mikołaj Sadowski, Agnieszka Łapczuk-Krygier, Agnieszka Kącka-Zych Radomir Jasiński

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Nicotines are a group of compounds containing conjugated pyridine and pyrrolidine molecular segments. They are widely applied in medicine, pharmacy, and agriculture. Namely as researched treatment of Alzheimer, depression, Parkinson's, Tourette syndrome, general nervous and mental disorders. Furthermore, nicotine itself is used as a stimulant, animal repellent and was widely applied as an insecticide. In our work, we obtained nicotine analogues with possible applications in agriculture. The synthesis employed [3+2] cycloaddition (32CA) reactions, occurring between pirydyl-functionalised nitrones and conjugated nitroalkenes, that allowed us to fully regio- and stereoselectively obtain product. Moreover, cycloaddition reaction realizes rapidly in mild conditions with the full atomic economy, thus fitting into “green chemistry” trends.

Keywords: nicotine, isoxazolidine, 1-3-dipolar cycloaddition, green chemistry, biological and pharmacological activity

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Authors: Abdelkader T. Ahmed

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Greywater is any wastewater draining from a household including kitchen sinks and bathroom tubs, except toilet wastes. Although this used water may contain grease, food particles, hair, and any number of other impurities, it may still be suitable for reuse after treatment. Greywater reusing serves two purposes including reduction the amount of freshwater needed to supply a household, and reduction the amount of wastewater entering sewer systems. This study aims to investigate and design a simple and cheap unit to treat the greywater in household via using ceramic membranes and reuse it in supplying water for toilet flushing. The study include an experimental program for manufacturing several tablet ceramic membranes from clay and sawdust with three different mixtures. The productivity and efficiency of these ceramic membranes were investigated by chemical and physical tests for greywater before and after filtration through these membranes. Then a treatment unit from this ceramic membrane was designed based on the experimental results of lab tests. Results showed that increase sawdust percent with the mixture increase the flow rate and productivity of treated water but decrease in the same time the water quality. The efficiency of the new ceramic membrane reached 95%. The treatment unit save 0.3 m3/day water for toilet flushing without need to consume them from the fresh water supply network.

Keywords: ceramic membranes, filtration, greywater, wastewater treatment

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Authors: R. Sarada Jayalakshmi Devi B. Bhaskar, S. Khayum Ahammed, T. N. V. K. V. Prasad

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Use of bioagents and biofungicides is safe to manage the plant diseases and to avoid human health hazards which improves food security. Myconanotechnology is the study of nanoparticles synthesis using fungi and their applications. The present work reports on preparation, characterization and antifungal activity of biogenic silver nanoparticles produced by the fungus Trichoderma sp. which was collected from groundnut rhizosphere. The culture filtrate of Trichoderma sp. was used for the reduction of silver ions (Ag+) in AgNO3 solution to the silver (Ag0) nanoparticles. The different ages (4 days, 6 days, 8 days, 12 days, and 15 days) of culture filtrates were screened for the synthesis of silver nanoparticles. Synthesized silver nanoparticles were characterized using UV-Vis spectrophotometer, particle size and zeta potential analyzer, Fourier Transform Infrared Spectrophotometer (FTIR) and Transmission Electron Microscopy. Among all the treatments the silver nitrate solution treated with six days aged culture filtrate of Trichoderma sp. showed the UV absorption peak at 440 nm with maximum intensity (0.59) after 24 hrs incubation. The TEM micrographs showed the spherical shaped silver nanoparticles with an average size of 30 nm. The antifungal activity of silver nanoparticles against Aspergillus niger causing collar rot disease in groundnut and aspergillosis in humans showed the highest per cent inhibition at 100 ppm concentration (74.8%). The results points to the usage of these mycogenic AgNPs in agriculture to control plant diseases.

Keywords: groundnut rhizosphere, Trichoderma sp., silver nanoparticles synthesis, antifungal activity

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Authors: Kamran Jawed, Anu Jose Mattam, Zia Fatma, Saima Wajid, Malik Z. Abdin, Syed Shams Yazdani

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Worldwide demand of natural and sustainable fuels and chemicals have encouraged researchers to develop microbial platform for synthesis of short chain fatty acids as they are useful precursors to replace petroleum-based fuels and chemicals. In this study, we evaluated the role of fatty acid synthesis and β-oxidation cycle of Escherichia coli to produce butyric acid, a 4-carbon short chain fatty acid, with the help of three thioesterases, i.e., TesAT from Anaerococcus tetradius, TesBF from Bryantella formatexigens and TesBT from Bacteroides thetaiotaomicron. We found that E. coli strain transformed with gene for TesBT and grown in presence of 8 g/L glucose produced maximum butyric acid titer at 1.46 g/L, followed by that of TesBF at 0.85 g/L and TesAT at 0.12 g/L, indicating that these thioesterases were efficiently converting short chain fatty acyl-ACP intermediate of fatty acid synthesis pathway into the corresponding acid. The titer of butyric acid varied significantly depending upon the plasmid copy number and strain genotype. Deletion of genes for fatty acyl-CoA synthetase and acyl-CoA dehydrogenase, which are involved in initiating the fatty acid degradation cycle, and overexpression of FadR, which is a dual transcriptional regulator and exerts negative control over fatty acid degradation pathway, reduced up to 30% of butyric acid titer. This observation suggested that β-oxidation pathway is working synergistically with fatty acid synthesis pathway in production of butyric acid. Moreover, accelerating the fatty acid elongation cycle by overexpressing acetyl-CoA carboxyltransferase (Acc) and 3-hydroxy-acyl-ACP dehydratase (FabZ) or by deleting FabR, the transcription suppressor of elongation, did not improve the butyric acid titer, rather favored the long chain fatty acid production. Finally, a balance between cell growth and butyric acid production was achieved with the use of phosphorous limited growth medium and 14.3 g/L butyric acid, and 17.5 g/L total free fatty acids (FFAs) titer was achieved during fed-batch cultivation. We have engineered an E. coli strain which utilizes the intermediate of both fatty acid synthesis and degradation pathway, i.e. butyryl-ACP and -CoA, to produce butyric acid from glucose. The strategy used in this study resulted in highest reported titers of butyric acid and FFAs in engineered E. coli.

Keywords: butenoic acid, butyric acid, Escherichia coli, fed-batch fermentation, short chain fatty acids, thioesterase

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Authors: Yemane Tadesse Gebreslassie, Fisseha Guesh Gebremeskel

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Nanotechnology has made remarkable advancements in recent years, revolutionizing various scientific fields, industries, and research institutions through the utilization of metal and metal oxide nanoparticles. Among these nanoparticles, copper oxide nanoparticles (CuO NPs) have garnered significant attention due to their versatile properties and wide-range applications, particularly, as effective antimicrobial and anticancer agents. CuO NPs can be synthesized using different methods, including physical, chemical, and biological approaches. However, conventional chemical and physical approaches are expensive, resource-intensive, and involve the use of hazardous chemicals, which can pose risks to human health and the environment. In contrast, biological synthesis provides a sustainable and cost-effective alternative by eliminating chemical pollutants and allowing for the production of CuO NPs of tailored sizes and shapes. This comprehensive review focused on the green synthesis of CuO NPs using various biological resources, such as plants, microorganisms, and other biological derivatives. Current knowledge and recent trends in green synthesis methods for CuO NPs are discussed, with a specific emphasis on their biomedical applications, particularly in combating cancer and microbial infections. This review highlights the significant potential of CuO NPs in addressing these diseases. By capitalizing on the advantages of biological synthesis, such as environmental safety and the ability to customize nanoparticle characteristics, CuO NPs have emerged as promising therapeutic agents for a wide range of conditions. This review presents compelling findings, demonstrating the remarkable achievements of biologically synthesized CuO NPs as therapeutic agents. Their unique properties and mechanisms enable effective combating against cancer cells and various harmful microbial infections. CuO NPs exhibit potent anticancer activity through diverse mechanisms, including induction of apoptosis, inhibition of angiogenesis, and modulation of signaling pathways. Additionally, their antimicrobial activity manifests through various mechanisms, such as disrupting microbial membranes, generating reactive oxygen species, and interfering with microbial enzymes. This review offers valuable insights into the substantial potential of biologically synthesized CuO NPs as an alternative approach for future therapeutic interventions against cancer and microbial infections.

Keywords: biological synthesis, copper oxide nanoparticles, microbial infection, nanotechnology

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Authors: Tony Ngoy Mbodi, Christophe Muanda

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Textile industry is considered as one of the most polluting sectors in terms of effluent volume of discharge and wastewater composition, such as dye, which represents an environmental hazard when discharged without any proper treatment. A study was conducted to investigate the capability of the use of recycled alum sludge (RAS) as an alternative treatment for the reduction of colour, chemical oxygen demand (COD), total dissolved solids (TDS) and pH adjustment from dye based synthetic textile industry wastewater. The coagulation/flocculation process was studied for coagulants of Alum:RAS ratio of, 1:1, 2:1, 1:2 and 0:1. Experiments on treating the synthetic wastewater using membrane filtration and adsorption with corn cobs were also conducted. Results from the coagulation experiment were compared to those from adsorption with corn cobs and membrane filtration experiments conducted on the same synthetic wastewater. The results of the RAS experiments were also evaluated against standard guidelines for industrial effluents treated for discharge purposes in order to establish its level of compliance. Based on current results, it can be concluded that reusing the alum sludge as a low-cost material pretreatment method into the coagulation/flocculation process can offer some advantages such as high removal efficiency for disperse dye and economic savings on overall treatment of the industry wastewater.

Keywords: alum, coagulation/flocculation, dye, recycled alum sludge, textile wastewater

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Authors: Maha J. Balgoon, Gehan A. Raouf, Safaa Y. Qusti, Soad S. Ali

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The main cause of Alzheimer disease (AD) was believed to be mainly due to the accumulation of free radicals owing to oxidative stress (OS) in brain tissue. The mechanism of the neurotoxicity of Aluminum chloride (AlCl3) induced AD in hippocampus Albino wister rat brain tissue, the curative & the protective effects of Lipidium sativum group (LS) water extract were assessed after 8 weeks by attenuated total reflection spectroscopy ATR-IR and histologically by light microscope. ATR-IR results revealed that the membrane phospholipid undergo free radical attacks, mediated by AlCl3, primary affects the polyunsaturated fatty acids indicated by the increased of the olefinic -C=CH sub-band area around 3012 cm-1 from the curve fitting analysis. The narrowing in the half band width(HBW) of the sνCH2 sub-band around 2852 cm-1 due to Al intoxication indicates the presence of trans form fatty acids rather than gauch rotomer. The degradation of hydrocarbon chain to shorter chain length, increasing in membrane fluidity, disorder and decreasing in lipid polarity in AlCl3 group were indicated by the detected changes in certain calculated area ratios compared to the control. Administration of LS was greatly improved these parameters compared to the AlCl3 group. Al influences the Aβ aggregation and plaque formation, which in turn interferes to and disrupts the membrane structure. The results also showed a marked increase in the β-parallel and antiparallel structure, that characterize the Aβ formation in Al-induced AD hippocampal brain tissue, indicated by the detected increase in both amide I sub-bands around 1674, 1692 cm-1. This drastic increase in Aβ formation was greatly reduced in the curative and protective groups compared to the AlCl3 group and approaches nearly the control values. These results were supported too by the light microscope. AlCl3 group showed significant marked degenerative changes in hippocampal neurons. Most cells appeared small, shrieked and deformed. Interestingly, the administration of LS in curative and protective groups markedly decreases the amount of degenerated cells compared to the non-treated group. Also the intensity of congo red stained cells was decreased. Hippocampal neurons looked more/or less similar to those of control. This study showed a promising therapeutic effect of Lipidium sativum group (LS) on AD rat model that seriously overcome the signs of oxidative stress on membrane lipid and restore the protein misfolding.

Keywords: aluminum chloride, alzheimer disease, ATR-IR, Lipidium sativum

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Authors: H. Benaldjia, N. Habib, F. Djefaflia, A. Nait-Merzoug, A. Harat, J. El-Haskouri, O. Guellati

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Currently, the technology has attracted knowledge of energy storage sources similar to batteries, capacitors and super-capacitors because of its very different applications in many fields with major social and economic challenges. Moreover, hydroxides have attracted much attention as a promising and active material choice in large-scale applications such as molecular adsorption/storage and separation for the environment, ion exchange, nanotechnology, supercapacitor for energy storage and conversion, electro-biosensing, and catalysts, due to their unique properties which are strongly influenced by their composition, microstructure, and synthesis method. In this context, we report in this study the synthesis of hydroxide-based nanomaterials precisely based on Ni and Fe using a simple hydrothermal method with mono and bi precursors at optimized growth conditions (6h-120°C). The obtained products were characterized using different techniques, such as XRD, FTIR, FESEM and BET, as well as electrochemical measurements.

Keywords: energy storage, Supercapacitors, nanocomposites, nanohybride, electro-active materials.

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Authors: Mahtab Makaremi Masouleh, Günter Wozniak

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This research is part of an interdisciplinary project, promoting the design of a light temporary installable textile defence system against flood. In case river water levels increase abruptly especially in winter time, one can expect massive extra load on a textile protective structure in term of impact as a result of floating debris and even tree trunks. Estimation of this impulsive force on such structures is of a great importance, as it can ensure the reliability of the design in critical cases. This fact provides the motivation for the numerical analysis of a fluid structure interaction application, comprising flexible slender shaped and free-surface water flow, where an accelerated heavy flotsam tends to approach the membrane. In this context, the analysis on both the behavior of the flexible membrane and its interaction with moving flotsam is conducted by finite elements based solvers of the explicit solver and implicit Abacus solver available as products of SIMULIA software. On the other hand, a study on how free surface water flow behaves in response to moving structures, has been investigated using the finite volume solver of Star CCM+ from Siemens PLM Software. An automatic communication tool (CSE, SIMULIA Co-Simulation Engine) and the implementation of an effective partitioned strategy in form of an implicit coupling algorithm makes it possible for partitioned domains to be interconnected powerfully. The applied procedure ensures stability and convergence in the solution of these complicated issues, albeit with high computational cost; however, the other complexity of this study stems from mesh criterion in the fluid domain, where the two structures approach each other. This contribution presents the approaches for the establishment of a convergent numerical solution and compares the results with experimental findings.

Keywords: co-simulation, flexible thin structure, fluid-structure interaction, implicit coupling algorithm, moving flotsam

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Authors: T. Bielewicz, S. Dogan, C. Klinke

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Two-dimensional, solution-processable semiconductor materials are interesting for low-cost electronic applications [1]. We demonstrate the synthesis of lead sulfide nanosheets and how their size, shape and height can be tuned by varying concentrations of pre-cursors, ligands and by varying the reaction temperature. Especially, the charge carrier confinement in the nanosheets’ height adjustable from 2 to 20 nm has a decisive impact on their electronic properties. This is demonstrated by their use as conduction channel in a field effect transistor [2]. Recently we also showed that especially thin nanosheets show a high carrier multiplication (CM) efficiency [3] which could make them, through the confinement induced band gap and high photoconductivity, very attractive for application in photovoltaic devices. We are already able to manufacture photovoltaic devices out of single nanosheets which show promising results.

Keywords: physical sciences, chemistry, materials, chemistry, colloids, physics, condensed-matter physics, semiconductors, two-dimensional materials

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Authors: Anna Piasek, Anna Szymkiewicz, Gabriela Wiktor, Jolanta Pulit-Prociak, Marcin Banach

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Carbon dots (CDs) have great potential for application in many fields of science. They are characterized by fluorescent properties that can be manipulated. The nanomaterial has many advantages in addition to its unique properties. CDs may be obtained easily, and they undergo surface functionalization in a simple way. In addition, there is a wide range of raw materials that can be used for their synthesis. An interesting possibility is the use of numerous waste materials of natural origin. In the research presented here, the synthesis of CDs was carried out according to the principles of Green chemistry. Beet molasses was used as a natural raw material. It has a high sugar content. This makes it an excellent high-carbon precursor for obtaining CDs. To increase the fluorescence effect, we modified the surface of CDs with silver (Ag-CDs) nanoparticles. The process of obtaining CQD was based on the hydrothermal method by applying microwave radiation. Silver nanoparticles were formed via the chemical reduction method. The synthesis plans were performed on the Design of the Experimental method (DoE). Variable process parameters such as concentration of beet molasses, temperature and concentration of nanosilver were used in these syntheses. They affected the obtained properties and particle parameters. The Ag-CDs were analyzed by UV-vis spectroscopy. The fluorescence properties and selection of the appropriate excitation light wavelength were performed by spectrofluorimetry. Particle sizes were checked using the DLS method. The influence of the input parameters on the obtained results was also studied.

Keywords: fluorescence, modification, nanosilver, molasses, Green chemistry, carbon dots

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Authors: Shweta Maheshwari, Anish Dua

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Hematological changes reflect the adverse effects of heavy metals on fish. Hematology is a valuable tool to evaluate pathological condition of the fish. It helps in diagnosing the structural and functional status of fish exposed to toxicants. Morphological alteration in erythrocytes due to environmental stress can be studied through ultra-structural analysis. The aim of the present study was to assess the toxicity of mercuric chloride on red blood cells of an air breathing fish, Channa punctatus. Fish were subjected to chronic experiments using three sublethal concentration of mercuric chloride (0.020mg/L, 0.027mg/L, 0.040mg/L) for a period of 15, 30 and 60 days. Exposed fish of all the three concentrations were subjected to a recovery period of 30 days. A control was maintained in tap water simultaneously. For SEM analysis, blood from caudal vein of fish was taken and examined at an accelerating voltage of 20kV. Scanning electron micrographs revealed elliptical shaped erythrocytes of control fish. Alterations in the erythrocyte morphology such as presence of spherocytes, membrane internalization, crenation of membrane and development of lobopodial projections were observed in the exposed fish. The study revealed that ultra-structural analysis appears to be a sensitive method to evaluate the toxicity of various toxicants to fish.

Keywords: Channa punctatus, erythrocytes, mercuric chloride, scanning electron microscopy

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Authors: Farideh Namvar, Rosfarizan Mohamed

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In the field of nanotechnology, the use of various biological units instead of toxic chemicals for the reduction and stabilization of nanoparticles, has received extensive attention. This use of biological entities to create nanoparticles has designated as “Green” synthesis and it is considered to be far more beneficial due to being economical, eco-friendly and applicable for large-scale synthesis as it operates on low pressure, less input of energy and low temperatures. The lack of toxic byproducts and consequent decrease in degradation of the product renders this technique more preferable over physical and classical chemical methods. The variety of biomass having reduction properties to produce nanoparticles makes them an ideal candidate for fabrication. Metal oxide nanoparticles have been said to represent a "fundamental cornerstone of nanoscience and nanotechnology" due to their variety of properties and potential applications. However, this also provides evidence of the fact that metal oxides include many diverse types of nanoparticles with large differences in chemical composition and behaviour. In this study, iron oxide nanoparticles (Fe3O4-NPs) were synthesized using a rapid, single step and completely green biosynthetic method by reduction of ferric chloride solution with brown seaweed (Sargassum muticum) water extract containing polysaccharides as a main factor which acts as reducing agent and efficient stabilizer. Antimicrobial activity against six microorganisms was tested using well diffusion method. The resulting S-IONPs are crystalline in nature, with a cubic shape. The average particle diameter, as determined by TEM, was found to be 18.01 nm. The S-IONPs were efficiently inhibited the growth of Listeria monocytogenes, Escherichia coli and Candida species. Our favorable results suggest that S-IONPs could be a promising candidate for development of future antimicrobial therapies. The nature of biosynthesis and the therapeutic potential by S-IONPs could pave the way for further research on design of green synthesis therapeutic agents, particularly nanomedicine, to deal with treatment of infections. Further studies are needed to fully characterize the toxicity and the mechanisms involved with the antimicrobial activity of these particles. Antioxidant activity of S-IONPs synthesized by green method was measured by ABTS (2, 2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (IC50= 1000µg) radical scavenging activity. Also, with the increasing concentration of S-IONPs, catalase gene expression compared to control gene GAPDH increased. For anti-angiogenesis study the Ross fertilized eggs were divided into four groups; the control and three experimental groups. The gelatin sponges containing albumin were placed on the chorioalantoic membrane and soaked with different concentrations of S-IONPs. All the cases were photographed using a photo stereomicroscope. The number and the lengths of the vessels were measured using Image J software. The crown rump (CR) and weight of the embryo were also recorded. According to the data analysis, the number and length of the blood vessels, as well as the CR and weight of the embryos reduced significantly compared to the control (p < 0.05), dose dependently. The total hemoglobin was quantified as an indicator of the blood vessel formation, and in the treated samples decreased, which showed its inhibitory effect on angiogenesis.

Keywords: anti-angiogenesis, antimicrobial, antioxidant, biosynthesis, iron oxide (fe3o4) nanoparticles, sargassum muticum, seaweed

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Authors: Bright Kwakye-Awuah, Elizabeth Von-Kiti, Isaac Nkrumah, Baah Sefa-Ntiri, Craig D. Williams

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Bauxite and kaolin from Ghana Bauxite Company mine site were used to synthesize zeolites. Bauxite served as the alumina source and kaolin the silica source. Synthesis variations include variation of aging time at constant crystallization time and variation of crystallization times at constant aging time. Characterization techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive x-ray analysis (EDX) and Fourier transform infrared spectroscopy (FTIR) were employed in the characterization of the raw samples as well as the synthesized samples. The results obtained showed that the transformations that occurred and the phase of the resulting products were coordinated by the aging time, crystallization time, alkaline concentration and Si/Al ratio of the system. Zeolites A, X, Y, analcime, Sodalite, and ZK-14 were some of the phases achieved. Zeolite LTA was achieved with short crystallization times of 3, 5, 18 and 24 hours and a maximum aging of 24 hours. Zeolite LSX was synthesized with 24 hr aging followed with 24 hr hydrothermal treatment whilst zeolite Y crystallized after 48 hr of aging and 24 hr crystallization. Prolonged crystallization time produced a mixed phased product. Prolonged aging times, on the other hand, did not yield any zeolite as the sample was amorphous. Increasing the alkaline content of the reaction mixture above 5M introduced sodalite phase in the final product. The properties of the final products were comparable to zeolites synthesized from pure chemical reagents.

Keywords: bauxite, kaolin, aging, crystallization, zeolites

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