Structural characterization, optical properties and in vitro bioactivity of mesoporous erbium-doped hydroxyapatite

We report the successful synthesis of mesoporous erbium doped hydroxyapatite (Er-HA, Ca10-xEr2x/3?x/3(PO4)6(OH)2) by using a rapid and efficient microwave assisted wet precipitation method. Characterization techniques like X-ray diffraction (XRD), Fourier transform infra-red (FTIR), X-ray fluorescence spectrometer (XRF), Brunauer, Emmett and Teller (BET) and transmission electron microscopy (TEM) were used to determine lattice parameters, particle size, degree of crystallinity, elemental composition, surface area and morphology of Er-HA. Results confirmed the formation of crystalline Er-HA having crystallite size of 25 nm with spherical and rod like morphology, while the TEM analysis confirmed the mesoporous nature of the particles. Optical spectra of Er-HA contained seven electron transitions, whereas blue shift in the energy band gap (Eg) was observed upon increase in Er3+ content. The photoluminescence (PL) spectra contained green and red emissions. In vitro bioactivity study conducted in SBF revealed that the incorporation of Er3+ ions into HA structure lead to the faster discharge of Er3+ ions resulting in intense growth of apatite grains on the surface of the Er-HA pellets with Ca/P ratio of 1.72

Students' Class Performance Prediction Using Machine Learning Classifiers

Nowadays, educational data mining is being employed as assessing tool for study and analysis of hidden patterns in academic databases which can be used to predict student's academic performance. This paper implements various machine learning classification techniques on students' academic records for results predication. For this purpose, data of MS(CS) students were collected from a public university of Pakistan through their assignments, quizzes, and sessional marks. The WEKA data mining tool has been used for performing all experiments namely, data pre-processing, classification, and visualization. For performance measure, classifier models were trained with 3- and 10-fold cross validation methods to evaluate classifiers' accuracy. The results show that bagging classifier combined with support vector machines outperform other classifiers in terms of accuracy, precision, recall, and F-measure score. The obtained outcomes confirm that our research provides significant contribution in prediction of students' academic performance which can ultimately be used to assists faculty members to focus low grades students in improving their academic records

PREPARATION AND CHARACTERIZATION OF ALKYL-THIOLS MONOLAYER ON GLASS SUBSTRATES BY MICROCONTACT PRINTING

ABSTRACT Surface modification is a fascinating method to tailor the surface of material properties such as hydrophilicity, roughness, surface charge and many more. The modification is not only limited to solid materials, but could be possibly extended to particular liquid surfaces. In this paper, surface modification of glass slides with self-assembled monolayers (SAMs) of (3-Mercaptopropyl) trimethoxysilane (MPTMS) was conducted by using a simple method of microcontact printing. Characterizations of the self-assembled monolayer were realized by 3 techniques; (1) Atomic Force Microscopy (AFM) to determine the height of self-assembled monolayer and obtain the topography image, (2) X-ray Photoelectron Spectroscopy (XPS) to further confirm the thiol groups were grafted on the surface and (3) Confocal Fluorescence Microscopy (CFM) to visualize the reaction between thiol terminal groups and fluorescent probe. From the experiment conducted, the result showed that the MPTMS was successfully stamped on glass substrates. AFM scanning images displayed the 0.8±0.2nm height of MPTMS, which matching the size of the MPTS molecules (0.7±0.05nm). XPS spectra indicated the appearance of the doublet structure in the S2p region (S2p3/2 and S2p1/2 levels of the S energy levels) with two peaks in binding energy of 162.8 and 163.8eV respectively. CFM imaging indicated the fluorescent patterns on glass substrates

Integration of biocatalysis with product separation

This thesis deals with the research carried out to develop a column system for the continuous production of optically pure esters of 2-chloropropionic acid (CPA) and 2-phenoxypropionic acid (PPA). Chapter 1 entitled introduction, explores the available literature. This chapter highlights the advantages and disadvantages of currently available methods for the resolution of CPA and PPA. Chapter two explains our strategies for the resolution of CPA and PPA. We highlight the possible routes and steps we envisage to be important for the efficient resolution and continuous production of CPA and PPA. Rest of the thesis deals with our attempts to establish the column reactor. The remaining thesis is divided into the following sections. Analytical section: development of chiral assay to determine the optical purity of the products. Methods developed to measure the progress of reaction, enzyme activity and protein contents. Ester synthesis: highlights the advantages and disadvantages of the various processes used to synthesis the substrates. Lipase search: all commercially available lipases were tested for their activities against the substrates and optimal combination were explored in more detail. Adsorption support: several macro reticular resin were tested for their adsorption affinity towards CPA, PPA and their esters and lipase. Conditions were optimised for lipase activity and substrate adsorption. Development of a column reactor: column reactor was set-up according to the conditions listed in above chapters. Column was characterised according to the purity, optical purity and yield of the products and residual substrate isolated. Discussion: results from all the research carried out are summarised in this chapter Future work: this chapter highlights the additional points seemed necessary to successfully establish the continuous process

In vitro thrombin dose response on madin darby canine kidney cell monolayer

Epithelial cells are known to play an important role in sustaining the airway barrier that may be impaired in certain inflammatory conditions. Recently, the use of thrombin has been reported to open the airway of patients with asthma as well as enhance the permeability of endothelial cell monolayers. We designed an in vitro model of Madin Darby Canine Kidney (MDCK) cells and the physiological functions of this model were evaluated by measuring the transepithelial resistance (TER). The epithelial cytoskeletal organization was observed by staining with Bisbenzimide and Rodamine-Phalloidin (BBZ-Phalloidin) and confirmed by fluorescence microscopy. Measurements of the TER generated values up to 2020 Ω/cm2. A dose response of thrombin was observed, showing the permeability changes in the MDCK monolayer and subsequent recovery. A relationship between TER values and cytoskeletal organization was also observed and discussed

Rapid synthesis of thermally stable hydroxyapaptite

We have optimized the wet precipitation synthesis of hydroxyapaptite to obtain thermally stable powder in the short time span of 3 min. Exposure of the reaction mixture to 1000 W microwave for 3 min furnished hydroxyapatite, which was thermally stable at temperatures up to 1200 °C. Powders were analyzed for phase purity using X-ray crystallography; chemical composition was studied using Fourier transform infrared spectroscopy while particle morphology was analyzed using scanning electron microscopy

Topological Invariants for the General Structure of Grape Seed Proanthocyanidins

In this paper, we formulate the degree-based topological indicessuch as first Zagreb index, second Zagreb index, third Zagreb index,atom bond connectivity index, geometric-arithmetic (GA) index, generalsum connectivity index, hyper-Zagreb index, augmented Zagreb index,© sum connectivity index and general Randic index R¸ (}) ; for ¸ =¡1; 1;¡1 2 ; 1 2 ª for grape seed Proanthocyanidins network. By usingabove-mentioned topological indices, this study provides us different outcomes.AMS (MOS) Subject Classification Codes: 05C09; 05C12; 05C90; 05C92Key Words: Vertex degree, edges, topological indices, grape seed Proanthocyanidins network

Quinone-rich polydopamine functionalization of yttria stabilized zirconia for apatite biomineralization: the effects of coating temperature

The use of yttria stabilized zirconia (YSZ) as biomedical implants is often offset by its bioinert nature that prevents its osseointegration to occur. Therefore, the functionalization of YSZ surface by polydopamine to facilitate the biomineralization of apatite layer on top of the coated film has incessantly been studied. In this study YSZ discs were first immersed in 2 mg/mL of stirred dopamine solution at coating temperatures between 25 and 80 °C. The specimens were then incubated for 7d in 1.5 SBF. The effect of coating temperature on the properties (chemical compositions and wettability) and the apatite mineralization on top of the generated films was investigated. It was found that at 50 °C, the specimen displayed the highest intensity of Ca 2p peak (1.55 ± 0.42 cps) with Ca/P ratio of 1.67 due to the presence of abundant quinone groups (CO). However, the hydrophilicity (40.9 ± 01.7°) was greatly improved at 60 °C accompanied by the highest film thickness of 306 nm. Therefore, it was concluded that the presence of high intensity of quinone groups (CO) in polydopamine film at elevated temperature affects the chelation of Ca2+ ions and thus enhance the growth of apatite layer on top of the functionalized YSZ surface

A novel dataset of date fruit for inspection and classification

Date fruit grading and inspection is a challenging and crucial process in the industry. The grading process requires skilled and experienced labour. Moreover, the labour turnover in the date processing industries has been increased regularly. Therefore, due to the lack of trained labour, the quality of date fruit is often compromised. It leads to fruit wastage and instability of fruit prices. Currently, deep learning algorithms have achieved the research community's attention in solving the problems in the agriculture sector. The pre-trained models like VGG16 and VGG19 have been applied for the classification of date fruit [1,2].Furthermore, machine learning techniques like K-Nearest Neighbors, Support Vector Machine, Random Forest and a few others [3–6] have been used for grading of date fruit. Therefore, classification and sorting of date fruit problems have become common in the industry. The classification and grading of date fruit needed a neat and clean dataset. In this article, an indigenous and state-of-the-art dataset of date fruit is offered. The dataset contains images of four date fruit varieties. It consists of 3004 pre-processed images of different classes and grades.Moreover, images have been sorted based on size as large, medium, and small. Additionally, it is graded based on the quality as grade 1, grade 2, and grade 3. This dataset is separated into eighteen different directories for the facilitation of the researchers. It may contribute to develop an intelligent system to grade and inspect date fruit. This system may add value to the sustainable economic growth of fruit processing industries and farmers locally and internationally

Surface modification of yttria stabilized zirconia via polydopamine inspired coating for hydroxyapatite biomineralization

Yttria stabilized zirconia (YSZ) has been widely used as biomedical implant due to its high strength and enhanced toughening characteristics. However, YSZ is a bioinert material which constrains the formation of chemical bonds with bone tissue following implantation. Inspired by the property of mussels, the surface of YSZ ceramics was functionalized by quinone-rich polydopamine to facilitate the biomineralization of hydroxyapatite. YSZ discs were first immersed in 2 mg/mL of stirred or unstirred dopamine solution at either 25 or 37 degrees C. The samples were then incubated in 1.5 simulated body fluid (SBF) for 7d. The effect of coating temperature for stirred and unstirred dopamine solutions during substrate grafting was investigated on the basis of chemical compositions, wettability and biomineralization of hydroxyapatite on the YSZ functionalized surface. The results revealed that the YSZ substrate grafted at 37 degrees C in stirred solution of dopamine possessed significantly improved hydrophilicity (water contact angle of 44.0 +/- 2.3) and apatite-mineralization ability (apatite ratio of 1.78). In summary, the coating temperature and stirring condition during grafting procedure affected the chemical compositions of the films and thus influenced the formation of apatite layer on the substrate during the biomineralization process