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  • Open access
  • 84 Reads
Use of Olive Mill Wastewater as a substrate for laccase production by fungi

The annual Olive oil production in Mediterranean countries is estimated to over 95% of world cultivation. Nevertheless, this process generates large amounts of wastes including Olive Mill Wastewaters (OMW) with approximately 3* 107 m3 per year which poses a critical problem for the environment due to their colossal concentration of salinity, organic matter, and phenolic compounds responsible for the phytotoxicity and microbial growth inhibitory effects. For these reasons, most attention has been agreed to determine the best strategy to reduce the phenol content of OMW. Laccases were recognized as the main enzymes implicated in the degradation of phenolics in OOW alongside this the use of halotolerant fungi offers potential applications for the production of enzymes able to retain good activity in saline environments. This work aimed to investigate the ability of halophilic fungi isolated from saline soil to produce laccase and degrade OMW on the agar plate method. For this purpose, 23 strains of fungi are isolated from the sebkha’s soil of Ain’Ezzmoul, Algeria on PDA plates. The same medium supplemented with Guaiacol was used to investigate the laccase production. Then the three positif laccasic strains obtained (GS7, GS15, and VS1) were examined for their ability to grow and decolorize OMW. Therefore, three phasic OMW were collected and prepared with several concentrations and solidified with 2% Agar. The strains GS7, GS15, and VS1 respectively were able to grow at OWW up to 50 %, 40 %, and 100 % but only GS15 showed a complete decolorization halo. This latter was tested to laccase production on OMW liquid medium and shows enzyme activities 114.90 U and 170.83 U on respectively 10% and 20% of unsupplemented OMW.

  • Open access
  • 146 Reads
Polynuclear silver(I) complex with thianthrene: structural characterization, antimicrobial activity and interaction with biomolecules
Published: 09 November 2020 by MDPI in 1st International Electronic Conference on Applied Sciences session Chemistry

Silver(I) complexes showed a wide range of applications in medicine as effective antiseptic, antibacterial and anti-inflammatory agents. Antimicrobial properties of silver(I) complexes have been well known since the successful use of cream containing silver(I) sulfadiazine for the treatment of burn wounds. The critical factor in determining the antimicrobial activity of silver(I) complexes is the type of the ligand donor atom bound to the Ag(I) ion. In this respect, in the last few decades, research has been focusing on the synthesis of silver(I) complexes with sulfur-donor ligands, including mercaptan, thioamide and thione ligands. Herein, new silver(I) complex with thianthrene (tia), [Ag(NO3)(tia)(H2O)]n, was synthesized by the reaction of AgNO3 with an equimolar amount of tia in ethanol/dichlormethane (v/v 1:1) at room temperature, and characterized by NMR, IR and UV-Vis spectroscopy and single-crystal X-ray diffraction analysis. The antimicrobial activity of the synthesized complex was evaluated against the broad panel of Gram-positive and Gram-negative bacteria and Candida spp. This complex showed significant activity toward important human pathogens Gram-positive Staphylococcus aureus and Candida parapsilosis with minimal inhibitory concentrations (MICs) being 3.91 µg/mL. The interaction of [Ag(NO3)(tia)(H2O)]n with calf thymus DNA (ctDNA) and bovine serum albumin (BSA) was studied to evaluate the binding affinity towards these biomolecules for possible insights on the mode of antimicrobial activity. The binding affinity of the investigated complex to BSA is higher than that for DNA, indicating that proteins could be more favorable binding sites for this complex in comparison to the nucleic acids.

  • Open access
  • 99 Reads
IoT Based Smart Healthcare Services for Rural Unprivileged People in Bangladesh: Current Situation and Challenges

Healthcare is in the midst of a mobile transformation, and recent research indicates there's no end in sight to mobile technology use in patient care. Number of patients like COPD, heart disease, diabetic, cancer, and others are increasing day by day. In Bangladesh nearly 70 % people are living in rural areas now due to Covid-19 pandemic the number have increased more. It is very difficult for the rural people to get instant access to healthcare service in our country. Basically in remote areas of Bangladesh the facilities of MBBS doctors are not available. People mostly get medical treatment from nearby pharmacy or they need to travel very far distance (city hospitals) for getting medical treatment. In order to get this medical treatment facilities of MBBS doctor’s patients need to spend a lot of money for the purpose of travel, visit of doctors, medical tests and others. Rural people are not much aware about the non communicable diseases. They need to travel to city area to avail the medical treatment when they are very sick due to lack of medical facilities. It is very difficult for older people to travel far distance for the getting of medical diagnostic and treatment facilities. In this scenarios, IoT based smart healthcare services will be very helpful for the rural unprivileged people of our country. Life expectance of the rural people will be increased through the use of this smart healthcare facilities. IoT based smart healthcare services mean monitoring the health of the patients through the use of Computers, Mobile phone Tab, mobile and web applications and other technological devices such as smart IoT based wireless sensors device. In Bangladesh there are very few private companies providing IoT based healthcare services for rural people. Basic tests are done in the remote centers using the smart wireless sensors based smart medical devices and patients physiological data are sent to specialist doctors in the city using mobile phone and through online in real time. Prescriptions are provided through the use of online portal. Patients at remote areas are getting medical facilities staying in their village area. There are also few companies who are providing diagnostic facilities only for basic medical parameters using smart digital sensors to make awareness for no communicable disease and to reduce the number of such patients. From the research and study it is noted that some companies have stopped their services after two years from the start of their journey due to some challenges and some companies are continuing their services. The main goal of this paper is to analyze the current state of situation of IoT based smart healthcare services for rural unprivileged people in Bangladesh, and highlights the challenges associated with it. In order to accomplish this goal, companies who are providing this type of healthcare services are introduced, the main challenges are identified, current situation of the IoT based healthcare services and status have been identified and discussed.

  • Open access
  • 77 Reads
Investigation of guided wave interaction with discontinuities in the axisymmetric damped waveguide

Cable structures are a significant part of any long-span bridges as they account for the primary load-bearing members. Due to pitting corrosion and other breakages, the load-carrying capacity of bridge cables is affected and it is of paramount importance for the bridge engineers and stakeholders to monitor the existing infrastructures. Structural health monitoring (SHM) techniques are utilized to monitor such incidents and one of the prominent methods is to practice guided ultrasonic wave propagation and acoustic emission (AE) monitoring. In this paper, the numerical modeling of wave scattering by a structural discontinuity (cable damage) in axisymmetric high strength steel wire - viscoelastic waveguide medium for analyzing the wave interaction by inhomogeneity. This paper discusses the hybrid standard three-dimensional finite element (3D FE) method and semi-analytical finite element (SAFE) method for numerical analysis of guided ultrasonic wave propagation. The AE signal characteristics are used to understand the wave interaction of the pitting corrosion (damage) in steel wire cable considered for the present research work.

  • Open access
  • 81 Reads
A novel low cost biosorbent of phenolic compounds from olive mill wastewaters

Olive oil is one of the most widely used oils in the world with economic importance for many countries. Olive oil extraction generates large amounts of solid (cake) and liquid waste (olive mill wastewater, OMW), that pose a chronic environmental problem due to their disposal of the produced wastes on the landfill and water recipients. Thus, the research community is in search of techniques, individually or in combination, in order to detoxify waste. The common treatment methods belong to a one-dimension waste treatment approach, which is depollution. A practical way to overcome the financial obstacle of depollution is to develop treatment schemes that combine depollution with recovery of valuable ingredients, such as phenolics. The toxicity of this waste is mainly due to the high concentration of phenolic compounds, which, however, have strong antioxidant activity, turning OMW into an economical raw material for the recovery of bioactive compounds. Adsorption is generally considered to be the most effective and low-cost method for the removal of phenolics. So far, few studies have been carried out using sorbents for the removal of phenolics from OMW. However, the relatively high initial cost and the need for a costly regeneration system render common sorbents less economically viable. The objective of this work was to develop and optimize a new method for OMW management, using bioabsorbents from the food industry (such as coffee waste). The obtained phenolics will be used as a functional component in enriched foods.

  • Open access
  • 77 Reads
An Automatic Blood Cell Separation Machine With Disease Detection System: Perspective Bangladesh

Blood is a connective tissue in which Red blood cells function to transport oxygen and it is normally in disk shape. The inherited disorder of blood includes hemoglobinopathies which are major public health problem in Bangladesh. Sickle cell disease refers to a group of genetic disorders characterized by presence of sickle hemoglobin, anemia, schizocyte , acute and chronic tissue injury to blockage of blood flow by abnormally shaped red cell . Schizocytes are also a key indicator of a life threatening condition affecting a human patient. In the modern context only the latest generation automated cell counters provide a means to flag their operators if a schizocyte is detected, and very few of them are able to provide a schizocyte count. For the implementation of this in this paper we have the primary focus of detecting schizocytes in peripheral blood smear images.

  • Open access
  • 76 Reads
Synthesis of novel urethane-dimethacrylate monomer containing two quaternary ammonium groups for applications in dentistry
Published: 09 November 2020 by MDPI in 1st International Electronic Conference on Applied Sciences session Chemistry

The aim of this study was to obtain a new urethane-dimethacrylate monomer. This monomer has a potential antibacterial activity due to the presence of two quaternary ammonium groups, which are able to interact with negatively charged bacterial cell walls. Thanks to the presence of two methacrylate groups, this monomer is able to copolymerize with other dimethacrylate monomers, including those currently used in dentistry. We successfully synthesized new urethane-dimethacrylate monomer via the three steps synthesis route. The designed procedure comprises the transesterification of methyl methacrylate with tertiary N-methyldiethanolamine, Menschutkin reaction of the tertiary amine with a methacrylate moiety (obtained in the previous step) with 1-bromohexadecane and preparation of urethane dimethacrylate resin by reacting the hydroxyl group of the quaternary amine (from the previous step) with the isocyanate groups of 2,4,4-trimethylhexamethylene diisocyanate. The chemical structure of the intermediate products obtained in the first two stages of the synthesis as well as the chemical structure of the final product were confirmed by nuclear magnetic resonance spectroscopy (1H NMR and 13C NMR) and by infrared spectroscopy (FT IR). 1H NMR, 13C NMR and FT IR analysis confirmed that the monomer chemical structure consists of two methacrylate groups, two quaternary ammonium groups, two urethane bonds and two alkyl side chains directly attached to the quaternary nitrogen atoms.

  • Open access
  • 93 Reads
Research of the influence of zinc ions on synthesis and properties of hydroxyapatite
Published: 09 November 2020 by MDPI in 1st International Electronic Conference on Applied Sciences session Materials

Hydroxyapatites modified with metal ions are the main inorganic components of bone tissue that are approved for use as components for biocomposites and coatings for surgical implants. This study examined prototypes of functional materials for bone implants based on hydroxyapatite modified with zinc ions. Zinc is an essential trace element necessary for many biochemical processes. Also zinc ions have antibacterial activity. Zinc-modified hydroxyapatites were obtained by liquid-phase microwave synthesis. By varying the content of zinc nitrate during the synthesis, a line of samples with different amounts of zinc moles (x = 0.1; 0.5; 0.9) was obtained. Elemental analysis was performed before and after the in vivo experiment. The composition and structure of the materials obtained were determined by X-ray phase analysis, X-ray microanalysis, and IR spectroscopy. To determine the antibacterial activity, the determination of the number of cells by Koch's method was used. Escherichia coli served as a test object. In vivo biocompatibility was assessed by subcutaneous implantation of samples into house mice (Mus musculus). As a result of the study, it was found that the obtained samples represent the phase of hydroxyapatite Ca5(PO4)3(OH) hex. Antibacterial activity and biocompatibility have been established. The studied materials have antimicrobial activity, the samples did not cause significant changes both in the internal organs and in the general condition of laboratory animals during the entire experiment. The work was carried out within the framework of a scientific project supported by the TSU Competitiveness Enhancement Program.

  • Open access
  • 90 Reads
Monitoring of the "twin towers" of Bologna in Italy

In this contribution, in which the preliminary outcomes on the monitoring of the "Garisenda" Tower are discussed, there are also briefly presented the results already obtained from the monitoring of the “Asinelli” Tower, carried out a few years ago by the Authors.

The two medieval Towers, recognized as the "twin towers" of Bologna, represent a remarkable symbol of the City and of the Italian Architectural Heritage.

The Asinelli Tower was built in 1109–1119. It rises to a height of 97.30 m above the ground, and show a deviation from verticality of 2.38 m.

The Garisenda Tower, built around the same time, is much smaller (48 metres) but with a steeper leaning (3.22 m) due to an early and more marked subsidence of soil and foundation.

The data collected during the AE monitoring period of the Asinelli Tower were analyzed to evaluate the damage progress in a certain region of the masonry structure and correlate it with other considered phenomena, such as the influence of vehicle traffic, seismic activity, and wind action.

To arrive at a comprehensive and objective evaluation of the structural conditions of the Garisenda Tower, whose monitoring is still ongoing, the results obtained by the AE technique are supplemented with data obtained from other zones of the structure subject to different stress-strain conditions or by means of other techniques.

Thanks to this arrangement, the AE signals distribution is related to the data measured by optical cables and a seismometer to obtain an objective correlations between the actions generated by the environment and the Tower damage.

  • Open access
  • 96 Reads
Magnetic ground state and electronic structure of binary Mn2Sb compound from ab initio calculations
Published: 09 November 2020 by MDPI in 1st International Electronic Conference on Applied Sciences session Materials

Manganese antimonide Mn2-xMxSb, where M is a 3d transition metal, is a prominent binary material due to its high Curie temperature and magnetocaloric properties accompanying the M-induced first-order phase transition for various compositions. In this work we employed modern ab initio approach to analyze the magnetic ground state and electronic structure of Mn2Sb for various types of long-range ordering. Mn2Sb has a tetragonal type crystal structure with the space group P4/nmm. The unit cell contains two magnetic types of sites Mn1 and Mn2, tetrahedrally and octahedrally surrounded by Sb atoms, respectively. The structure is stable over a wide temperature range, with the magnetic structure passing through a series of phase transitions. The magnetic phase transition in Mn2Sb occurs at the Curie temperature about 550 K. Below this temperature, a ferrimagnetic ordering with unequal magnetic moments of different types of manganese ions is realized in the compound. The ferrimagnetic structure is formed by an antiparallel arrangement of magnetic moments with different magnitude of the Mn magnetic moments and found to have the lowest total energy. We obtained the Mn magnetic moments as approximately -3.5 and 2.3 Bohr magnetons in a good agreement with experimental data. In the electronic structure of Mn2Sb, it was found to possess the semi-metallic properties with a gap in the minority spin projection.