Search results for: reactive filler

Authors: Nadeem Bashir, Ghulam Mustafa Peerzada

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The present study pertains to the nonlinear behavior of acetaminophen based uncatalyzed Belousov-Zhabotinsky (BZ) oscillator and its dynamics in the presence of Ferroin as the catalyst. The role of free metal ions as catalysts was examined and the results compared with corresponding complexed catalysts. Free metal ions were found to be sluggish with respect to the evolution of the oscillatory regime as compared to complexed ones. Effect of change of the ligand moiety of the catalyst complex on the oscillatory parameters was monitored. Since ethanol potentiates the hepatotoxicity caused by acetaminophen in-vivo, it is thought to understand this interaction by virtue of causing perturbation of the acetaminophen based oscillator with different concentrations of the ethanol with and without ferroin as the catalyst. Another dimension to the ethanol effect was added by perturbation of the system with ethanol at different stages of the reaction so as to get an idea whether it is acetaminophen or some reactive intermediate generated in the reaction system which reacts with ethanol. Further, the ferroin-catalyzed oscillator is taken as a prototype inorganic model of the acetaminophen-ethanol syndrome, as ferroin and HOBr were inorganic replacements to Cyt P450 and NADPH in the alcohol metabolism.

Keywords: Belousov-Zhabotinsky reaction, ferroin, Paracetamol-Ethanol syndrome, kinetics

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Authors: Sang Beom Kim, Kyung Ju Kim, Myung Hoon Cho, Ji Hoon Kim, Soo Hyung Kim

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In this study, we systematically investigated the effect of nanoscale energetic materials in formulations of aluminum nanoparticles (Al NPs; heat source)/copper oxide nanoparticles (CuO NPs; oxidizer) on the combustion and gas-generating properties of sodium azide microparticles (NaN3 MPs; gas-generating agent) for potential applications in gas generators. The burn rate of the NaN3 MP/CuO NP composite powder was only ~0.3 m/s. However, the addition of Al NPs to the NaN3 MP/CuO NP matrix caused the rates to reach ~5.3 m/s, respectively. In addition, the N2 gas volume flow rate generated by the ignition of the NaN3 MP/CuO NP composite powder was only ~0.6 L/s, which was significantly increased to ~3.9 L/s by adding Al NPs to the NaN3 MP/CuO NP composite powder. This suggested that the highly reactive NPs, with the assistance of CuO NPs, were effective heat-generating sources enabling the complete thermal decomposition of NaN3 MPs upon ignition. Al NPs were highly effective in the gas generators because of the increased reactivity induced by the reduced particle size. Finally, we successfully demonstrated that a homemade airbag with a specific volume of ~140 mL could be rapidly and fully inflated by the thermal activation of nanoscale energetic material-added gas-generating agents (i.e., NaN3 MP/Al NP/CuO NP composites) within the standard time of ~50 ms for airbag inflation.

Keywords: nanoenergetic materials, aluminum nanoparticles, copper oxide nanoparticles, gas generators

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Authors: Gul Afreen, Sreedevi Upadhyayula, Mahendra K. Sunkara

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One-dimensional (1D) nanostructures like nanowires, nanotubes, and nanorods find variety of practical application owing to their unique physico-chemical properties. In this work, TiO₂ nanowires were synthesized by direct oxidation of titanium particles in a unique microwave plasma jet reactor. The prepared TiO₂ nanowires manifested the flexible features, and were characterized by using X-ray diffraction, Brunauer-Emmett-Teller (BET) surface area analyzer, UV-Visible and FTIR spectrophotometers, Scanning electron microscope, and Transmission electron microscope. Further, the photodegradation efficiency of these nanowires were tested against toxic organic dye like methylene blue (MB) and the results were compared with the commercial TiO₂. It was found that TiO₂ nanowires exhibited superior photocatalytic performance (89%) as compared to commercial TiO₂ (75%) after 60 min of reaction. This is attributed to the lower recombination rate and increased interfacial charge transfer in TiO₂ nanowire. Pseudo-first order kinetic modelling performed with the experimental results revealed that the rate constant of photodegradation in case of TiO₂ nanowire was 1.3 times higher than that of commercial TiO₂. Superoxide radical (O₂˙⁻) was found to be the major contributor in the photodegradation mechanism. Based on the trapping experiments, a plausible mechanism of the photocatalytic reaction is discussed.

Keywords: heterogeneous catalysis, photodegradation, reactive oxygen species, TiO₂ nanowires

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Authors: Yvonne Dedzo

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Social media has become a powerful tool in bridging the distance between individuals regardless of their location. It has become a convenient platform for public discussion and, consequently, generated the phenomenon of citizen journalists who have become both proactive and reactive participants in the dissemination of news, information and other epochal and historical events. This phenomenon has fueled the growth of niche authorities who deliver exceptional democratically consequential information online. This study, therefore, investigates how some selected niche authorities maintain their status on social media. Using the selective processes theory, the study further interrogates the information shared by niche authorities and further analyses the extent to which a public interest-altruistic motive or personal interest-self-serving motive drives their agenda of new sharing and usage. Through cyber-ethnography and, qualitative content analysis and semi-structured interviews, data was gathered and analysed from the posts of two purposely selected niche authorities on Facebook and Twitter. The findings indicate that niche authorities maintain their status by being consistent, prompt, informative, resourceful and interactive in their postings on the social media platform. The study also discovered that even though niche authorities are motivated by both public interest-altruism and interest-self-serving, the latter had a higher of motivation than the former.

Keywords: social medida, citizen journalist, niche authorities, selective processes theory

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Authors: Tengfei He, Mengjie Zhang, Baosheng Jin

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In this study, the low-cost halloysite (Hal) was utilized for the first time to enhance the solid-phase enrichment and stability of heavy metals (HMs) during solid waste pyrolysis through experimental and theoretical methods, and compared with kaolinite (Kao). Experimental results demonstrated that Hal was superior to Kao in improving the solid-phase enrichment of HMs. Adding Hal reduced the proportion of HMs in the unstable fraction (F1+F2), consequently lowering the environmental risk of biochar and the extractable state of HMs. Through Grand canonical Monte Carlo and Density Functional Theory (DFT) simulations, the adsorption amounts and adsorption mechanisms of Cd/Pb compound on Hal/Kao surfaces were analyzed. The adsorption amounts of HMs by Hal were significantly higher than Kao and decreased with increasing temperature, and the difference in adsorption performance caused by structural bending was negligible. The DFT results indicated that Cd/Pb monomers were stabilized by establishing covalent bonds with OH or reactive O atoms on the Al-(0 0 1) surface, whereas the covalent bonds with ionic bonding properties formed between Cl atoms and unsaturated Al atoms played a crucial role in stabilizing HM chlorides. This study highlights the potential of Hal in stabilizing HMs during pyrolysis without requiring any modifications.

Keywords: heavy metals, halloysite, density functional theory, grand canonical Monte Carlo

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Authors: Sakinah Abdullah, Rosna Mat Taha

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Antioxidants are compounds that protect cells against the damaging effects of reactive oxygen species such as singlet oxygen, superoxide, peroxyl radicals, and peroxynitrite which result in oxidative stress leading to cellular damage. Natural antioxidant are in high demand because of their potential in health promotion and disease prevention and their improved safety and consumer acceptability. Plants are rich sources of natural antioxidant. Dioscorea alata L. known as 'ubi badak' in Malaysia were well known for their antioxidant content, but this plant was seasonal. Thus, tissue culture technique was used to mass propagate this plant. In the present work, a comparative study between in vitro (from tissue culture) and in vivo (from intact plant) samples of Dioscorea alata L. for their antioxidant potential by 2,2-diphenil -1- picrylhydrazyl (DPPH) radical scavenging activity method and their total phenolic and flavonoid contents were carried out. All samples had better radical scavenging activity but in vivo samples had the strongest radical scavenging activity compared to in vitro samples. Furthermore, tubers from in vivo samples showed the greatest free radical scavenging effect and comparatively greater phenolic content than in vitro samples.

Keywords: Dioscorea alata, tissue culture, antioxidant, in vivo, in vitro, DPPH

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Authors: V. Antevska, B. Dejanova, L. Todorovska, J. Pluncevic, E. Sivevska, S. Petrovska, S. Mancevska, I. Karagjozova

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Introduction: The aim of this study was to optimise the laboratory oxidative stress (OS) markers in soccer players. Material and methods: In a number of 37 soccer players (21±3 years old) and 25 control subjects (sedenters), plasma samples were taken for d-ROMs (reactive oxygen metabolites) and NO (nitric oxide) determination. The d-ROMs test was performed by measurement of hydroperoxide levels (Diacron, Italy). For NO determination the method of nitrate enzyme reduction with the Greiss reagent was used (OXIS, USA). The parameters were taken after the training of the soccer players and were compared with the control group. Training was considered as maximal exercise treadmill test. The criteria of maximum loading for each subject was established as >95% maximal heart rate. Results: The level of d-ROMs was found to be increased in the soccer players vs. control group but no significant difference was noticed. After the training d-ROMs in soccer players showed increased value of 299±44 UCarr (p<0.05). NO showed increased level in all soccer players vs. controls but significant difference was found after the training 102±29 μmol (p<0.05). Conclusion: Due to these results we may suggest that the measuring these OS markers in sport medicine may be useful for better estimation and evaluation of the training program. More oxidative stress should be used to clarify optimization of the training intensity program.

Keywords: oxidative stress markers, soccer players, training, sport

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Authors: Z. Mazrouei-Sebdani, A. Khoddami, H. Hadadzadeh, M. Zarrebini

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Silica aerogels are well-known meso-porous materials with high specific surface area (500–1000 m2/g), high porosity (80–99.8%), and low density (0.003–0.8 g/cm3). However, the silica aerogels generally are highly brittle due to their nanoporous nature. Physical and mechanical properties of the silica aerogels can be enhanced by compounding with the fibers. Although some reports presented incorporation of the fibers into the sol, followed by further modification and drying stages, no information regarding the aerogel powders as filler in the polymeric fibers is available. In this research, waterglass based aerogel powder was prepared in the following steps: sol–gel process to prepare a gel, followed by subsequent washing with propan-2-ol, n-Hexane, and TMCS, then ambient pressure drying, and ball milling. Inspired by limited dust releasing, aerogel powder was introduced to the PET electrospinning solution in an attempt to create required bulk and surface structure for the nano fibers to improve their hydrophobic and insulation properties. The samples evaluation was carried out by measuring density, porosity, contact angle, sliding angle, heat transfer, FTIR, BET and SEM. According to the results, porous silica aerogel powder was fabricated with mean pore diameter of 24 nm and contact angle of 145.9º. The results indicated the usefulness of the aerogel powder confined into nano fibers to control surface roughness for manipulating superhydrophobic nanowebs with sliding angle of 5˚ and water contact angle of 147º. It can be due to a multi-scale surface roughness which was created by nanowebs structure itself and nano fibers surface irregularity in presence of the aerogels while a laye of fluorocarbon created low surface energy. The wettability of a solid substrate is an important property that is controlled by both the chemical composition and geometry of the surface. Also, a decreasing trend in the heat transfer was observed from 22% for the nano fibers without any aerogel powder to 8% for the nano fibers with 4% aerogel powder. The development of thermal insulating materials has become increasingly more important than ever in view of the fossil energy depletion and global warming that call for more demanding energy-saving practices.

Keywords: Superhydrophobicity, Insulation, Sol-gel, Surface energy, Roughness.

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Authors: Basheer Idrees Balarabe, Aminu Hamisu Kura, Nabila Shehu

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As the power demand rapidly increases, the generation and transmission systems are affected because of inadequate resources, environmental restrictions and other losses. The role of transient stability control in maintaining the steady-state operation in the occurrence of large disturbance and fault is to describe the ability of the power system to survive serious contingency in time. The application of a Unified power flow controller (UPFC) plays a vital role in controlling the active and reactive power flows in a transmission line. In this research, a genetic algorithm (GA) method is applied to determine the optimal location of the UPFC device in a power system network for the enhancement of the power-system Transient Stability. Optimal location of UPFC has Significantly Improved the transient stability, the damping oscillation and reduced the peak over shoot. The GA optimization Technique proposed was iteratively searches the optimal location of UPFC and maintains the unusual bus voltages within the satisfy limits. The result indicated that transient stability is improved and achieved the faster steady state. Simulations were performed on the IEEE 14 Bus test systems using the MATLAB/Simulink platform.

Keywords: UPFC, transient stability, GA, IEEE, MATLAB and SIMULINK

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Authors: R. F. B. Gonçalves, E. N. Iwama, J. A. F. F. Rocco, K. Iha

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Propellants based on Hydroxyl Terminated Polybutadiene/Ammonium Perchlorate (HTPB/AP) are the most commonly used in most of the rocket engines used by the Brazilian Armed Forces. This work aimed at the possibility of extending its useful life (currently in 10 years) by performing kinetic-chemical analyzes of its energetic material via Differential Scanning Calorimetry (DSC) and also performing computer simulation of aging process using the software Large-scale Atomic/Molecular Massively Parallel Simulator (LAMMPS). Thermal analysis via DSC was performed in triplicates and in three heating ratios (5 ºC, 10 ºC, and 15 ºC) of rocket motor with 11 years shelf-life, using the Arrhenius equation to obtain its activation energy, using Ozawa and Kissinger kinetic methods, allowing comparison with manufacturing period data (standard motor). In addition, the kinetic parameters of internal pressure of the combustion chamber in 08 rocket engines with 11 years of shelf-life were also acquired, for comparison purposes with the engine start-up data.

Keywords: shelf-life, thermal analysis, Ozawa method, Kissinger method, LAMMPS software, thrust

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Authors: Saleh Alkarri, Melinda Frame, Dimple Sharma, John Cairney, Lee Maddan, Jin H. Kim, Jonathan O. Rayner, Teresa M. Bergholz, Muhammad Rabnawaz

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Reported herein is an investigation of anti-bacterial and anti-virus properties, mode of action of Mg(OH)₂ and copper-infused Mg(OH)₂ nanoplatelets (NPs) on melt-compounded and thermally embossed polypropylene (PP) surfaces. The anti-viral activity for the NPs was studied in aqueous liquid suspensions against SARS-CoV-2, and the mode of action was investigated on neat NPs and PP samples that were thermally embossed with NPs. Anti-bacterial studies for melt-compounded NPs in PP confirmed approximately 1 log reduction of E. coli populations in 24 h, while for thermally embossed NPs, an 8 log reduction of E. coli populations was observed. In addition, the NPs exhibit anti-viral activity against SARS-CoV-2. Fluorescence microscopy revealed that reactive oxygen species (ROS) is the main mode of action through which Mg(OH)₂ and Cu-Infused Mg(OH)₂act against microbes. Plastics with anti-microbial surfaces from where biocides are non-leachable are highly desirable. This work provides a general fabrication strategy for developing anti-microbial plastic surfaces.

Keywords: anti-microbial activity, E. coli K-12 MG1655, anti-viral activity, SARS-CoV-2, copper-infused magnesium hydroxide, non-leachable, ROS, compounding, surface embossing, dyes

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Authors: Amin Kamal Akhnoukh, Lois Zaki Kamel, Magued Mourad Barsoum

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The objective of this research is to mitigate and prevent the alkali silica reactivity (ASR) in highway construction projects. ASR is a deleterious reaction initiated when the silica content of the aggregate reacts with alkali hydroxides in cement in the presence of relatively high moisture content. The ASR results in the formation of an expansive white colored gel-like material which forms the destructive tensile stresses inside hardened concrete. In this research, different types of local aggregates available in the State of Arkansas were mixed and mortar bars were poured according to the ASTM specifications. Mortar bars expansion was measured versus time and aggregates with potential ASR problems were detected. Different types of supplementary cementitious materials (SCMs) were used in remixing mortar bars with highly reactive aggregates. Length changes for remixed bars proved that different types of SCMs can be successfully used in reducing the expansive effect of ASR. SCMs percentage by weight is highly dependent on the SCM type. The result of this study will help avoiding future losses due to ASR cracking in construction project and reduce the maintenance, repair, and replacement budgets required for highways network.

Keywords: alkali silica reaction, aggregates, misture, cracks, Mortar Bar Test, supplementary cementitious materials

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Authors: M. Khaledi Pour, P. Akbartehrani, M. Amini, M. Khani, M. Mohajeri Tehrani, R. Radi, B. Shokri

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Diabetic Foot Ulcer (DFU) is one of the costly severe complications of diabetes. Neuropathy and Peripheral Arterial Disease (PAD) due to diabetes are significant causes of this complication. In 10 years the patients with DFUs are twice as likely to die as patients without DFUs. Cold Atmospheric Plasma (CAP) is a promising tool for medical purposes. CAP generate reactive species at room temperature and are effective in killing bacteria and fibroblast proliferation. These CAP-based tools produce NO, which has bactericidal and angiogenesis properties. It also showed promising effects in the DFUs surface reduction and the time to wound closure. In this paper, we evaluated the effect of the Argon Plasma Jet (APJ) on the healing process of the Wagner Grade 2 DFUs in a randomized clinical trial. The 20 kHz sinusoidal voltage frequency derives the APJ. Patients (n=20) were randomly double-blinded assigned into two groups. These groups receive the standard care (SC, n=10) and the standard care with APJ treatment (SC+APJ, n=10) for five sessions in four weeks. The results showed that the APJ treatment along standard care could reduce the wound surface by 20 percent more than the standard care. Also, It showed a more influential role in controlling wound infection.

Keywords: argon plasma jet, cold atmospheric plasma, diabetes, diabetic foot ulcer

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Authors: Maesoomeh Khorshidi Mehr, Mohammad Sajadian, Shadi Alipour

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The purpose of the present study was to compare the effects of eight weeks of continuous and periodic aerobic exercises on serum levels of CRP in overweight woman. 36 woman aged between 20 and 35 years from the city of Ahwaz were randomly selected as the sample of the study. This sample was further divided into three groups (n= 12) of continuous aerobic exercise, periodic aerobic exercise, and control. Subjects of the groups of continuous and periodic aerobic exercise participated in 8 weeks of specialized exercises while the control group subjects did not take part in any regular physical activity program. Blood samples were collected from subjects in 24 hours prior to and 48 hours past to the intervention period. Afterwards, the serum level of CRP was measured for each blood sample. Results showed that BMI and serum level of CRP both significantly reduced as a result of aerobic exercises. However, no statistically significant difference was recorded between the extent of effects of the former and latter aerobic exercise types. Eight weeks of aerobic exercise will probably result in reduced inflammation and cardiovascular diseases risk in overweight women. The reason for lack of difference between effects of continuous and periodic aerobic exercise may lie in the similarity of average intensity and length of physical administered activities.

Keywords: heart diseases, aerobic exercise, inflammation, CRP, overweight

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Authors: Bashar Al-Sabti, Jehad Harbali

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Background: Pyridine is a reactive base that might be used in preparing sitagliptin. International Agency for Research on Cancer classifies pyridine in group 2B; this classification means that pyridine is possibly carcinogenic to humans. Therefore, pyridine should be monitored at the allowed limit in sitagliptin pharmaceutical ingredients. Objective: The aim of this study was to develop a novel ultra high performance liquid chromatography mass spectrometry (UHPLC-MS) method to estimate the quantity of pyridine impurity in sitagliptin pharmaceutical ingredients. Methods: The separation was performed on C8 shim-pack (150 mm X 4.6 mm, 5 µm) in reversed phase mode using a mobile phase of water-methanol-acetonitrile containing 4 mM ammonium acetate in gradient mode. Pyridine was detected by mass spectrometer using selected ionization monitoring mode at m/z = 80. The flow rate of the method was 0.75 mL/min. Results: The method showed excellent sensitivity with a quantitation limit of 1.5 ppm of pyridine relative to sitagliptin. The linearity of the method was excellent at the range of 1.5-22.5 ppm with a correlation coefficient of 0.9996. Recoveries values were between 93.59-103.55%. Conclusions: The results showed good linearity, precision, accuracy, sensitivity, selectivity, and robustness. The studied method was applied to test three batches of sitagliptin raw materials. Highlights: This method is useful for monitoring pyridine in sitagliptin during its synthesis and testing sitagliptin raw materials before using them in the production of pharmaceutical products.

Keywords: genotoxic impurity, pyridine, sitagliptin, UHPLC -MS

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Authors: Kave Moloudi, Heidi Abrahamse, Blassan P. George

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Radiotherapy (RT) and photodynamic therapy (PDT) are both forms of cancer treatment that aim to kill cancer cells while minimizing damage to healthy tissue. The similarity between RT and PDT lies in their mechanism of action. Both treatments use energy to damage cancer cells. RT uses high-energy radiation to damage the DNA of cancer cells, while PDT uses light energy to activate a photosensitizing agent, which produces reactive oxygen species (ROS) that damage the cancer cells. Both treatments require careful planning and monitoring to ensure the correct dose is delivered to the tumor while minimizing damage to surrounding healthy tissue. They are also often used in combination with other treatments, such as surgery or chemotherapy, to improve overall outcomes. However, there are also significant differences between RT and PDT. For example, RT is a non-invasive treatment that can be delivered externally or internally, while PDT requires the injection of a photosensitizing agent and the use of a specialized light source to activate it. Additionally, the side effects and risks associated with each treatment can vary. In this review, we focus on generalizing the 6Rs of radiobiology in PDT, which can open a window for the clinical application of Radio-photodynamic therapy with minimum side effects. Furthermore, this review can open new insight to work on and design new radio-photosensitizer agents in Radio-photodynamic therapy.

Keywords: radiobiology, photodynamic therapy, radiotherapy, 6Rs in radiobiology, ROS, DNA damages, cellular and molecular mechanism, clinical application.

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Authors: Yantao Li, Jun Zheng

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Food poison caused by consumption of contaminated food, especially seafood, is one of most serious public health threats worldwide. Vibrio parahaemolyticus is emerging bacterial pathogen and the leading cause of human gastroenteritis associated with food poison, especially in the southern coastal region of China. To successfully cause disease in host, bacterial pathogens need to overcome the host-derived stresses encountered during infection. One of the toxic chemical species elaborated by the host is nitric oxide (NO). NO is generated by acidified nitrite in the stomach and by enzymes of the inducible NO synthase (iNOS) in the host cell, and is toxic to bacteria. Bacterial pathogens have evolved some mechanisms to battle with this toxic stress. Such mechanisms include genes to sense NO produced from immune system and activate others to detoxify NO toxicity, and genes to repair the damage caused by toxic reactive nitrogen species (RNS) generated during NO toxic stress. However, little is known about the NO resistance in V. parahaemolyticus. In this study, a transposon coupled with next generation sequencing (Tn-seq) technology will be utilized to identify genes for NO resistance in V. parahaemolyticus. Our strategy will include construction the saturating transposon insertion library, transposon library challenging with NO, next generation sequencing (NGS), bioinformatics analysis and verification of the identified genes in vitro and in vivo.

Keywords: vibrio parahaemolyticus, nitric oxide, tn-seq, virulence

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Authors: Ayse Demirbas, Bruce A. Welt, Yavuz Yagiz

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Oxidation of polyunsaturated fatty acids (PUFA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in fish causes loss of product quality. Oxidative rancidity causes loss of nutritional value and undesirable color changes. Therefore, powerful antioxidant extracts may provide a relatively low cost and natural means to reduce oxidation, resulting in longer, higher quality and higher value shelf life of foods. In this study, we measured effects of red cabbage antioxidant on lipid oxidation in fresh tilapia filets using thiobarbituric acid reactive substances (TBARS) assay, peroxide value (PV) and color assesment analysis. Extraction of red cabbage was performed using an efficient microwave method. Fresh tilapia filets were dipped in or sprayed with solutions containing different concentrations of extract. Samples were stored for up to 9 days at 4°C and analyzed every other day for color and lipid oxidation. Results showed that treated samples had lower oxidation than controls. Lipid peroxide values on treated samples showed benefits through day-7. Only slight differences were observed between spraying and dipping methods. This work shows that red cabbage antioxidant extracts may represent an inexpensive and all natural method for reducing oxidative spoilage of fresh fish.

Keywords: antioxidant, shelf life, fish, red cabbage, lipid oxidation

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Authors: Bhavini Patel, Aslihan Ugun-Klusek, Ellen Billet

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The two main contributing factors to familial and idiopathic form of Parkinson’s disease (PD) are oxidative stress and altered proteolysis. Monoamine oxidase-A (MAO-A) plays a significant role in redox homeostasis by producing reactive oxygen species (ROS) via deamination of for example, dopamine. The ROS generated induces chemical modification of proteins resulting in altered biological function. The ubiquitin-proteasome system, which consists of three different types or proteolytic activity, namely “chymotrypsin-like” activity (CLA), “trypsin-like” activity (TLA) and “post acidic-like” activity (PLA), is responsible for the degradation of ubiquitinated proteins. Defects in UPS are known to be strongly correlated to PD. Herein, the effect of ROS generated by MAO-A on proteasome activity and the effects of proteasome inhibition on MAO-A protein levels in WT, mock and MAO-A overexpressed (MAO-A+) SHSY5Y neuroblastoma cell lines were investigated. The data in this study report increased proteolytic activity when MAO-A protein levels are significantly increased, in particular CLA and PLA. Additionally, 20S proteasome inhibition induced a decrease in MAO-A levels in WT and mock cells in comparison to MAO-A+ cells in which 20S proteasome inhibition induced increased MAO-A levels to be further increased at 48 hours of inhibition. This study supports the fact that MAO-A could be a potential pharmaceutical target for neuronal protection as data suggests that endogenous MAO-A levels may be essential for modulating cell death and survival.

Keywords: monoamine oxidase, neurodegeneration, Parkinson's disease, proteasome

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Authors: Husham Bayazed

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The infant immune system has a reputation for being weak and underdeveloped when compared to the adult immune system, but the comparison isn’t quite fair. At the start, as the COVID-19 pandemic drags on and evolves, many Pediatricians and kids' parents have been left with renewed questions about the consequences and sequel of infection on children and the steps to be taken if their child, has the symptoms of COVID-19 or tests positive. Recent Findings: Literature reviews and recent studies revealed that children are better than adults at controlling SARS-CoV-2. There was conflicting evidence on age-related differences in ACE2 expression in the nose and lungs. But scientists who measured the ‘viral load’ in children's upper airways have seen no clear difference between children and adults. Moreover, the hypothesis is that kids might be more exposed to other coronaviruses common cold with a production of ready protective antibodies to lock on to the pandemic coronavirus. But the evidence suggests that adults also have this immunity too. Strikingly, these ‘cross-reactive’ antibodies don’t offer any special protection. Summary: One of the few silver linings of the Covid-19 pandemic is that children are relatively spared. The kid's Innate Immunity is hardly the whole story, the innate immune response against SARS-CoV-2 infection is early initiative calm with low immunological tone to prevent an overactive immunity and with rapidly repair damage to the lungs in contrast to stormy waves in adults. Therefore, Kids are at much lower risk of Covid-19 infection and they are still winning the battle against Covid-19 with their innate immunity.

Keywords: kids, Covid-19, immunity, ACT2

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Authors: Debasish Das, Mainak Mitra, A.Chaudhuri

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For the purpose of producing moisture vapor permeable waterproof cotton fabric to be used for protective apparel against rain, cotton fabric was coated with the blend of natural rubber and chloroprene rubber containing ammonium acetate as the water-soluble salt, employing a calendar coating technique. Rubber formulations also contained filler, homogenizer, and a typical sulphur curing system. Natural rubber and chloroprene blend in the blend ratio of 30: 70, containing 25 parts of sodium acetate per hundred parts of rubber was coated on the fabric. The coated fabric was vulcanized thereafter at 140oC for 3 h. Coated and vulcanized fabric was subsequently dipped in water for 45 min, followed by drying in air. Such set of treatments produced optimum results. Coated, vulcanized, washed and dried cotton fabric showed optimum developments in the property profiles in respect of waterproofness, breathability as revealed by moisture vapor transmission rate, coating adhesion, tensile properties, abrasion resistance, flex endurance and fire retardancy. Incorporation of highly water-soluble ammonium acetate salt in the coating formulation and their subsequent removal from vulcanized coated layer affected by post washing in consequent to dipping in the water-bath produced holes of only a few microns in the coating matrix of the fabric. Such microporous membrane formed on the cotton fabric allowed only transportation of moisture vapor through them, giving a moisture vapor transmission rate of 3734 g/m2/24h, while acting as a barrier for large liquid water droplet resisting 120cm of the water column in the hydrostatic water-head tester, rendering the coated cotton fabric waterproof. Examination of surface morphology of vulcanized coating by scanning electron microscopy supported the mechanism proposed for development of breathable waterproof layer on cotton fabric by the process employed above. Such process provides an easy and cost-effective route for achieving moisture vapor permeable waterproof cotton.

Keywords: moisture vapour permeability, waterproofness, chloroprene, calendar coating, coating adhesion, fire retardancy

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Authors: Michal Natan, Ori Gutman, Shlomo Margel, Ehud Banin

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Biofilm formation is a serious problem in medical and industrial settings due to the increased resistance of these communities to killing compared to free-living bacteria. This has prompted the search for agents that can inhibit both bacterial growth and biofilm formation. In this study, N-halamine rechargeable nanoparticles (NPs) were synthesized by co-polymerization of the monomer methacryl amide and the cross-linker monomer N,N-methylene bisacryl amide, and were subsequently loaded with Cl+, using bleach. The chlorinated NPs exhibited remarkable stability to organic reagents. The antibacterial mechanism of the P(MAA-MBAA)-Cl NPs involved generation of reactive oxygen species (ROS) only upon exposure to organic media, but not upon incubation in water, suggesting a specific activation. Moreover, a unique interaction of the P(MAA-MBAA)-Cl NPs with Staphylococcus aureus bacteria but not with human cells was discovered, whereby these microorganisms were all specifically targeted and marked for destruction. Finally, in collaboration with Netafim Ltd. irrigation drippers containing the P(MAA-MBAA)-Cl were incubated in the field and were shown to prevent fouling on them for 5 months as opposed to the control drippers that exhibited substantial fouling. Further, the NPs offer recharging to the surface, thus providing long-lasting protection that does not exist in the products available today. Taken together, the results demonstrate the great potential of implementing the charged NPs in devices and surfaces to prevent bacterial growth.

Keywords: bacteria, biofilm, fouling, nanoparticles

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Authors: Anusha Bhardwaj, Shekhar Shinde

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Nitric oxide (NO•) has been documented in research papers as one of the most versatile player in the therapeutics. It is identified as a biological multifunctional messenger molecule which is synthesized by the action of nitric oxide synthase (NOS) enzyme from L-arginine. The protective and the toxic effect in conjunction form the complete picture of the biological function of nitric oxide in humans. The dual nature is because of various factors such as concentration of NO, the isoform of NOS involved, type of cells in which it is synthesized, reaction partners like proteins, reactive oxygen intermediates, prosthetic groups, thiols etc., availability of the substrate L-arginine, intracellular environment in which NO is produced and generation of guanosine 3, 5’- cyclic monophosphate (cGMP). Activation of NOS through infection or trauma leads to one or more systemic effects including enhanced immune activity against invading pathogens, vaso/bronchodilatation in the cardiovascular and respiratory systems and altered neurotransmission which can be protective or toxic. Hence, NO affects the balance between healthy signaling and neurodegeneration in the brain. In lungs, it has beneficial effects on the function of airways as a bronchodilator and acts as the neurotransmitter of bronchodilator nerves. Whereas, on the other hand, NO may have deleterious effects by amplifying the asthmatic inflammatory response and also act as a vasodilator in the airways by increasing plasma exudation. But NOS Inhibitors and NO donors hamper the signalling pathway and hence a therapeutic application of NO is compromised.

Keywords: nitric oxide, multifunctional, dual nature, therapeutic applications

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Authors: Khalid Ali, Manar Jammal

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In order to meet the stringent latency and reliability requirements of the upcoming 5G networks, Open Radio Access Networks (O-RAN) have been proposed. The virtualization of O-RAN has allowed it to be treated as a Network Function Virtualization (NFV) architecture, while its components are considered Virtualized Network Functions (VNFs). Hence, intelligent Machine Learning (ML) based solutions can be utilized to apply different resource management and allocation techniques on O-RAN. However, intelligently allocating resources for O-RAN VNFs can prove challenging due to the dynamicity of traffic in mobile networks. Network providers need to dynamically scale the allocated resources in response to the incoming traffic. Elastically allocating resources can provide a higher level of flexibility in the network in addition to reducing the OPerational EXpenditure (OPEX) and increasing the resources utilization. Most of the existing elastic solutions are reactive in nature, despite the fact that proactive approaches are more agile since they scale instances ahead of time by predicting the incoming traffic. In this work, we propose and evaluate traffic forecasting models based on the ML algorithm. The algorithms aim at predicting future O-RAN traffic by using previous traffic data. Detailed analysis of the traffic data was carried out to validate the quality and applicability of the traffic dataset. Hence, two ML models were proposed and evaluated based on their prediction capabilities.

Keywords: O-RAN, traffic forecasting, NFV, ARIMA, LSTM, elasticity

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Authors: Giovanni Meloni

Abstract:

Recent results are presented from experiments carried out at the Advanced Light Source (ALS) at the Chemical Dynamics Beamline of Lawrence Berkeley National Laboratory using multiplexed synchrotron photoionization mass spectrometry. The reaction mixture and a buffer gas (He) are introduced through individually calibrated mass flow controllers into a quartz slow flow reactor held at constant pressure and temperature. The gaseous mixture effuses through a 650 μm pinhole into a 1.5 mm skimmer, forming a molecular beam that enters a differentially pumped ionizing chamber. The molecular beam is orthogonally intersected by a tunable synchrotron radiation produced by the ALS in the 8-11 eV energy range. Resultant ions are accelerated, collimated, and focused into an orthogonal time-of-flight mass spectrometer. Reaction species are identified by their mass-to-charge ratios and photoionization (PI) spectra. Comparison of experimental PI spectra with literature and/or simulated curves is routinely done to assure the identity of a given species. With the aid of electronic structure calculations, potential energy surface scans are performed, and Franck-Condon spectral simulations are obtained. Examples of these experiments are discussed, ranging from new intermediates characterization to reaction mechanisms elucidation and biofuels oxidation pathways identification.

Keywords: mass spectrometry, reaction intermediates, synchrotron photoionization, oxidation reactions

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Authors: Talat Baran

Abstract:

Palladium-catalyzed Suzuki coupling reactions are powerful ways for synthesis of biaryls compounds and so far different palladium sources as have been used in catalyst systems. However, the high cost of the ligands using as support materials for palladium ion and so researchers have explored alternative low-cost support materials such as silica, cellule and zeolite. A natural polymer chitosan is suitable for support material because of it unique properties such as eco-friendly, renewable, abundant, low cost, biodegradable and it has free reactive -NH2 and –OH groups. Especially, pendant amino groups of chitosan can easily react with carbonyl groups of aldehyde or ketone by Schiff base formation and thus palladium ions can coordinate with imine groups of Schiff base. This purpose, in this study, firstly a new chitosan Schiff base supported palladium (II) catalyst was synthesized and its chemical structure was characterized with FT-IR, SEM/EDAX, XRD, TG-DTG, ICP-OES and magnetic moment techniques. Then catalytic performance of the catalyst was investigated in Suzuki cross coupling reactions under simple and fast microwave heating methods. Also, recycle activity of palladium catalyst was tested under optimum condition and the catalyst showed long life time. At the end of catalytic performance tests of chitosan supported palladium (II) catalysts indicated high turnover numbers, turnover frequency and selectivity with very small loading catalyst

Keywords: catalyst, chitosan, Schiff base, Suzuki coupling

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Authors: Zerzouri Nora, Benalia Nadia, Bensiali Nadia

Abstract:

This paper presents a grid-connected wind power generation scheme using Doubly Fed Induction Generator (DFIG). This can supply power at constant voltage and constant frequency with the rotor speed varying. This makes it suitable for variable speed wind energy application. The DFIG system consists of wind turbine, asynchronous wound rotor induction generator, and inverter with Space Vector Modulation (SVM) controller. In which the stator is connected directly to the grid and the rotor winding is in interface with rotor converter and grid converter. The use of back-to-back SVM converter in the rotor circuit results in low distortion current, reactive power control and operate at variable speed. Mathematical modeling of the DFIG is done in order to analyze the performance of the systems and they are simulated using MATLAB. The simulation results for the system are obtained and hence it shows that the system can operate at variable speed with low harmonic current distortion. The objective is to track and extract maximum power from the wind energy system and transfer it to the grid for useful work.

Keywords: Doubly Fed Induction Generator, Wind Energy Conversion Systems, Space Vector Modulation, distortion harmonics

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Authors: Somaieh Salehpour, Douglas Ireland, Chris Anderson, Charles Markessini

Abstract:

Over the last few years, advancements have been made around improving sustainability for wood composite boards. One of the last and most challenging sustainability hurdles is finding a viable alternative to petroleum-based resin binders. In today’s market, no longer is formaldehyde emission control sufficient to meet the requirements of many architects and end-use consumers. Even the use of highly reactive isocyanates is considered by many as not sustainable enough since these chemicals are manufactured from classical fossil fuel sources. The emergence of biopolymers specifically engineered for usage as wood composite binders has been successfully demonstrated in this paper as a viable option towards a truly renewable wood composite board. Recent technology advancements driven by EcoSynthetix and CHIMAR have exploited the advantages of using an engineered biopolymer. The evidence shows that this renewable technology has the potential to be used as a partial up to full replacement of classical formaldehyde technologies. Numerous trials, both in the lab and at industrial scale, have shown that a renewable binder of the proposed technology can produce a commercially viable board in a traditional industrial setting. The ultimate goal of this work is to provide evidence that a sustainable binder alternative can be used to make a commercial board while at the same time improving the total cost of manufacturing.

Keywords: no added formaldehyde, renewable, biopolymers, sustainable wood composites, engineered biopolymers

Procedia PDF Downloads 401

Authors: HengJiang Cai, RuiJin Zhang, JinSong Gui

Abstract:

Enhanced UV-B (280-320nm) radiation resulting from ozone depletion was one of the global environmental problems. The effects of enhanced UV-B radiation on marine macro-algae were exposed to be the greatest in shallow intertidal environments because the macro-alga was often at or above the water during low tide. Ulva pertusa Kjellman was belonged to Chlorophyta (Phylum), Ulvales (Order), Ulvaceae (Family) which was widely distributed in the western Pacific coast, and the resources were extremely rich in China. Therefore, the effects of UV-B radiation on the growth of Ulva pertusa seedling were studied in this research. Ulva pertusa seedling appearances were mainly characterized by rod shapes and tadpole shapes. The percentage of rod shapes was 90.68%±2.50%. UV-B radiation could inhibit the growth of Ulva pertusa seedling, and the growth inhibition was more significant with the increased doses of UV-B radiation treatment. The relative inhibition rates of Ulva pertusa seedling length were16.11%, 24.98%and 39.04% respectively on the 30th day at different doses (30.96, 61.92 and 123.84 Jm-2d-1) of UV-B radiation. Ulva pertusa seedling had emerged death under UV-B radiation, and the death rates were increased with the increased doses of UV-B radiation treatment. Physiology and biochemistry of Ulva pertusa seedling could be affected by UV-B radiation treatment. The SOD (superoxide dismutase) activity was increased at low-dose UV-B radiation (30.96 Jm-2d-1), while was decreased at high-dose UV-B radiation (61.92 and 123.84 Jm-2d-1). UV-B radiation could inhibit CAT (catalase) activity all the while. It speculated that the reasons for growth inhibition and death of Ulva pertusa seedling were excess ROS (reactive oxygen species), which produced by UV-B radiation.

Keywords: growth, physiology and biochemistry, Ulva pertusa Kjellman, UV-B radiation

Procedia PDF Downloads 281

Authors: Seoyoun Kim, Chunghee Park

Abstract:

Microplastics have recently become an issue due to their potentially harmful effects on the marine environment and the human body. The purpose of this study is to investigate the correlation of fiber emissions during the home laundering with the fabric parameters such as yarn density, warp/weft density, and weave structure. Also, the effect of finishing treatments such as reactive dyeing, water-repellent finish, peach skin finish on fiber emissions was evaluated. Furthermore, we studied the biodegradability of fibers in the marine environment compared to those in soil burial and the impact of finishing treatment on the biodegradability. Biodegradability was evaluated by measuring BOD values and tensile strength reduction. The results showed that more fibers were released in the thicker yarn, lower weave density. Also, a weave structure which has less compactness, released more fibers. Peach skin finish with microfibers exposed on the surface caused more fiber release, whereas water-repellent finish reduced the fiber emission. In addition, the biodegradability of the fabrics submerged in the marine environment were lower compared with those buried in the soil. Also, the water-repellent fabric was less biodegradable than the untreated one. Further research is suggested considering the fabrics with various chemical components or geometry and their fouling behavior in the marine environment.

Keywords: biodegradation, fibers, microplastic, pollution

Procedia PDF Downloads 137