133 research outputs found
ORIGINAL ARTICLE Synthesis of A Novel Interpenetrating Polymer Network Hydrogel as Drug Delivery System Hossein Hosseinzadeh; Synthesis of A Novel Interpenetrating Polymer Network Hydrogel as Drug Delivery System
No full textABSTRACT The present study is aimed at developing novel type of interpenetrating polymeric network (IPN) hydrogels of chitosan with poly(acrylic acid) for the controlled release of amphetamine drug. IPN hydrogels were synthesized by simultaneous polymerization/crosslinking of acrylic acid monomer in the presence of chitosan and crosslinker. The swelling properties and in vitro drug release characteristics of IPN hydrogels have been investigated in detail. Variation in composition of the IPN was achieved by varying the concentration of crosslinker. In addition, these IPNs were characterized for their pH-sensitive behaviour by equilibrium swelling studies. It was observed that the release of amphetamine was much higher at pH 7.4 compared to pH 1.2, indicating that the release system is controllable and can be as a release system for intestine specific drug delivery
Isolating, characterizing, and engineering novel Cu-proteins and peroxidases
Get PDFMetalloproteins are a fascinating class of proteins that function at the heart of several important biological processes including photosynthesis, respiration, and nitrogen fixation. It is even more amazing, considering that nature uses a small set of tertiary structures and metal centers to perform all these different functions with efficiency and selectivity. How nature tunes the activity within these scaffolds has been the area of research for many years. The goal of this work is to understand the underlying mechanisms of such tuning with a special focus on the role of subtle changes of residues in the secondary coordination sphere of the metal ion, an underexplored area of study. I use protein engineering techniques not only to shed light on the mechanisms underlying such changes, but also to design new functionalities within our scaffold proteins and to enhance their properties for specific purposes, such as fuel generation.
This work is divided into three main sections. In the first, I focus on characterizing a novel metalloprotein, N. mar_1307, from the organism Nitrosopumilus maritimus. While the protein shares a protein fold and Type 1 copper coordination site with other common electron transfer cupredoxins, the lack of an axial residue creates an open binding position in the Cu center, leading to a novel enzymatic function, NO oxidation. The purification, characterization, and activity assays of the protein are described in detail in chapter 2.
The second and major focus of this work is on tuning the reduction potential of azurin, a common electron transfer protein. In chapter 3 I demonstrate that how by making mutations around the Cu site, and replacing Cu with Ni I can obtain an azurin variant with a reduction potential of nearly 1V, the highest potential that can be observed under physiological conditions, along with other variants with negative potentials. Chapter 4 describes the characterization of a series of Phe114 mutants that were used to understand the role of this critical secondary sphere residue in tuning the reduction potential of the Cu site. Chapter 5 demonstrates the Marcus inverted region of electron transfer in a series of azurin variants with different reduction potentials. Finally, I show my initial attempts toward the design of a high-throughput screening platform for the directed evolution of azurin in chapter 6.
In chapters 7 and 8, I focus on the design of novel functionalities in one of our model scaffolds, cytochrome c peroxidase (CcP). Chapter 7 describes the work done to enhance the Mn(II) oxidation activity in a designed model of manganese peroxidase within the CcP scaffold based on modifications of the second coordination sphere around the Mn(II) binding site. In chapter 8 I report the design and characterization of a novel CcP variant that shows catalase-like activity in “as-purified” form and forms a heme-protein crosslink in the heme-bound form.Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2017-12-01The student, Parisa Hosseinzadeh, accepted the attached license on 2015-09-17 at 11:09.The student, Parisa Hosseinzadeh, submitted this Dissertation for approval on 2015-09-17 at 11:57.This Dissertation was approved for publication on 2015-10-08 at 14:46.DSpace SAF Submission Ingestion Package generated from Vireo submission #8686 on 2016-03-02 at 14:11:52Made available in DSpace on 2016-03-02T20:57:17Z (GMT). No. of bitstreams: 2
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Magnetar+Bump Modeling of Superluminous Supernovae
No full textThese data files are associated with the article "Bumpy Declining Light Curves are Common in Hydrogen-poor Superluminous Supernovae." This repository contains four directories, described below.
MOSFiT Output Files
The "mosfit" directory contains the raw output files from the Modular Open-Source Fitter for Transients (Guillochon et al. 2017). See its documentation for the output format. Keep in mind that some detections have been converted into nondetections in these files (see the paper for a full explanation), so you should not use them as a source for the photometry.
Magnetar Models
The "models" directory contains the range of models for each supernova. These are stored as ECSV files, which can be read using Astropy tables. The columns are MJD, filter, apparent magnitude (median, minimum, maximum), and absolute magnitude (median, minimum, maximum). The metadata contains the median and standard deviation of each parameter discussed in the paper, as well as the supernova name, distance modulus, and extinction.
Magnetar Parameters
The "params" directory contains the magnetar model parameters corresponding to each model realization, also stored as ECSV files. In other words, you can use these files to reproduce the posterior for each parameter. The metadata contains the units for each parameter and a LaTeX representation of each variable name.
Bump Models
The "bumps" directory contains the raw output for the bump modeling. These are stored as compressed Numpy files (.npz) and can be read using np.load. The keywords are as follows:
"chain": the flattened MCMC chain, stored as a 2D array. The 0th dimension corresponds to the number of walkers times the number of steps. The 1st dimension corresponds to the parameters: amplitude, center (MJD), and FWHM (observed days). In the case of 2 bumps, the parameters are amplitude 1, center 1, FWHM 1, amplitude 2, center 2, FWHM 2.
"pmed": the median of each parameter, followed by the median absolute deviation for each parameter (converted to a standard deviation).
"energies": the integrated energy in each model realization (in watt-days).
"energy": the median of the “energies” array.
"denergy": the median absolute deviation of the “energies” array (converted to a standard deviation).
"integral": the integral of the magnetar residuals before modeling (in watt-days). This is not used in the paper.
"t0" and "t1": the range of MJDs used in the bump fitting.
If you have any questions about this dataset, feel free to contact the author, Griffin Hosseinzadeh
Corresponding Author Effects of Tarragon Powders' Different Levels (Artemisia Dracunculus) on Performance and Carcasses 'Characteristics male Broiler chickens
No full textABSTRACT This study was designed to investigate the effects of different levels of Tarragon powder on performance and carcass' characteristics of broiler chickens. 200 one-day-old Ross 308 male broiler chickens in a completely randomized design with 4 treatments and 5 replicates per treatment and 10 birds in each replicate were used. Experimental diets were set on the basis of corn-soy-wheat and Ross 308 broiler chickens nutritional requirements tables by the use of UFFDA ration formulation software for each of the (1-21 days) and (22-42 days) period. Treatments were: base diet (control), base diet + 0.125% of Tarragon powder, base diet + 0.25% of Tarragon powder, base diet + 0.5% of Tarragon powder.The results of experiment showed that experimental dietaries caused no significant difference between the Feed Intake of different treatments statistically (P>0.05). The consumption of experimental rations increased body weight in control treatment and 0.125% Tarragon treatment when compared with powder 0.5%Tarragon powder treatments in 1-21 days old (P<0.01). It also decreased the body weight in 0.5%Tarragon powder treatment when compared with control treatment significantly in 1-42 days old (P<0.05). The consumption of experimental rations caused significant increasing of 0.5%Tarragon powder treatment's Feed conversion ratio when compared with control treatment and 0.125% Tarragon powder treatment in 1-21 days old (P<0.05) as well as in 1-42 days old (P<0.01).The consumption of experimental rations caused significant decrease of 0.5%Tarragon powder treatments' production efficiency index when compared with control treatment and 0.125% Tarragon powder in 1-42 days old (P<0.01). The consumption of experimental rations caused significant increase of 0.5%Tarragon powder treatment Mortality rate when compared with control treatment and 0.125% Tarragon powder in 1-42 days old (P<0.01). The consumption of experimental rations had no significant effect on the relative weight of breast, thigh, cookable carcasses and abdominal fat of different treatments in the whole process of husbandry in 1-42 days old (p>0.05). It seems that adding Artemisia dracunculus (Tarragon) powder 0.5%level to the broiler chicken's rations can decrease the body weight when compared with the body Hosseinzadeh et al . Int J Adv Biol Biom Res. 2014; 2(5):1750-1760 1751 | Page weight of other treatments; accordingly this can lead to significant increase of this treatment's feed ratio conversion when compared with other treatments
An investigation of the overlapping passive zones using a novel geotechnical centrifuge model
No full textTo improve the design of soil retaining walls in narrow trenches, a design optimization tool is introduced by Hosseinzadeh and Joosse (2015). This design optimisation tool is an intensification factor on the passive earth pressure coefficient Kp, that includes the effect of overlapping passive zones. The authors argue that the passive earth pressure coefficient due to the overlap of passive zones is larger compared to the passive earth pressure coefficient in case of unrestrained passive zone development. The intensification factor XKp is defined as the ratio between the unrestrained ultimate passive capacity and the restrained ultimate passive capacity, the magnitude is dependent on the dimensions of the narrow trench. The authors observe that the intensification factor increases non-linear when the dimensions of the trench decreases. The numerical study of Hosseinzadeh and Joosse (2015) is based on theoretical assumptions of the Hardening Soil model in the Finite Element Modelling (FEM) software Plaxis 2D. To improve the understanding of the intensification effect and to validate the numerical study, a novel physical scale model is developed which models the unrestrained passive zone development and the effect due to the overlap of passive zones. To simulate realistic stress levels in the model, a geotechnical centrifuge is used where earth’s gravity is enlarged by high speed rotation of the model. Multiple sand characterization tests are performed to obtain the parameters of the Delft Centrifuge (DC) sand. Furthermore, interface characterization tests are performed to obtain the friction parameters playing a role in the physical model. Various centrifuge tests at 80g and 100g are performed in the geotechnical centrifuge facility of the Delft University of Technology. An actuator in the strongbox is connected to a stiff wall. During translation of the wall towards the soil body, the load and the wall displacement are measured. The wall represents a prototype embedded length (d) of 5 m in all the tests. Restrained passive soil behaviour is modelled symmetrically in the strongbox and the width (w) of the narrow trench is varied in the test series. An ultimate passive load is measured by the plateau state and visible by the full development of the shear band for w/d ratios of 6.4, 3.0, 2.0 and 1.5. It can be concluded from the physical model tests that the intensification effect is observed in the model results. The ultimate passive load (indicated by the plateau state) is larger in models with a smaller w/d ratio. The intensification factor displays a non-linear increasing trend for decreasing model dimensions w/d. The curvature of the trend line is similar to the trend observed in the numerical study by Hosseinzadeh and Joosse (2015). This thesis shows however discrepancies between definition and the absolute values of the intensification factor of the numerical model and the physical model. The physical model tests show significant larger ultimate passive capacities and intensification factors compared to the numerical study. When small wall displacements are compared, the restrained physical model does not show significant differences compared to the unrestrained physical model. The passive zones need to be mobilized before they can overlap. This conclusion is not made in the numerical simulation, the intensification effect is noticeable directly after the start of prescribed wall displacement. Limitations of the constitutive model and the simplified shear characteristics of the soil mass are the main reasons to explain the differences between the numerical and physical model. It is recommended to study the effect of the overlapping passive zones on sand samples with different grain size distributions and different packings. To increase the understanding of the intensification effect and to increase the applicability for engineering practice, stratification and different types of soil have to be included in further research.Geo-engineeringGeoscience & EngineeringCivil Engineering and Geoscience
Numerical assessment and validation of a swelling rock model
No full textIn this research project, an assessment and validation of a swelling rock model (Benz, 2012), which is applicable to anhydrite swelling rock, was carried out through the Soil Test Facility of PLAXIS2D Finite Element Software. The validation process was conducted through the simulation of different element tests including stress-controlled oedometer test, and strain-controlled uniaxial compression test. A sensitivity analysis and parameter variations were carried out within the aforementioned tests. The obtained results and recommendations from this study can be used for conducting a case study of tunnelling within swelling rock. This will help to give a better understanding of swelling deformation occurrence around an excavation leading to a better tunnel support design. Furthermore, the way by which the swelling rock model parameters should be dealt with for a practical application is provided.Applied Earth Sciences; Erasmus Mundus Minerals and Environmental Programme (EMMEP)Geoscience & EngineeringCivil Engineering and Geoscience
Providing a Model for Detecting Personality of People in Social Networks
No full textDocumentos apresentados no âmbito do reconhecimento de graus e diplomas estrangeirosThe exponential growth of the use of social networks in cyberspace has led individuals to share a lot of information, including image, voice and text.
Analyzing social Networks data provides details information about individual personality. The complexity and large volume of extracted data is that such that it requires to apply machine learning algorithms. In this paper the author has analyzed the behavior patterns using writing. we first need to know the standard personality models. one of the most reliable models is MBTI model. the goal of this thesis is to find a supervised Learning model that can determine personality factors by people writing in social networks. due to the fact that experience has shown for complex problems with many parameters, deep learning methods can be more effective, we used deep learning model and two personality factors are considered an introversion - extroversion and intuition - sensing. The obtained results show a good accuracy which based on we were able to distinguish an introversion - extroversion personality factor with precision of 62 % accuracy and intuition – sensing factor with precision of 58
An Author Gender Detection Method Using Whale Optimization Algorithm and Artificial Neural Network
No full textAuthor gender detection (AGD) is a serious and crucial issue in Internet security applications, in particular in email, messenger, and social network communications. Detecting the gender of communication partner helps preventing massive fraud and abuses happening through social media such as email, blogs, forums. Text and writings of people on the Internet have valuable information that can be used to identify the gender of an author. Machine learning and meta-heuristic algorithms are valuable techniques to extract hidden patterns useful for detecting gender of a text. In this paper, an artificial neural network (ANN) is employed as a classifier to detect the gender of an email author and the whale optimization algorithm (WOA) is used to find optimal weights and biases for improving the accuracy of the ANN classification. Through this combination of ANN and WOA an accuracy of 98%, precision of 97.16%, and recall of 99.67% were achieved, which indicates the superiority of the proposed method on Bayesian networks, regression, decision tree, support vector machine, and ANN examined
Corrections to “An Author Gender Detection Method Using Whale Optimization Algorithm and Artificial Neural Network”
No full textPresents corrections to the paper, (Corrections to “An Author Gender Detection Method Using Whale Optimization Algorithm and Artificial Neural Network”)
A Review of the Role of Human Capital in the Organization
No full textAbstractToday, the concepts of human capital and strategic management of human resources are very common in the organizations in terms of philosophy and technique. The term of “human capital” is considered as a key element in improving the assets of an organization, since it is a sustainable competitive advantage and increases the employees’ efficiency. Some organizational theorists apply the rules of human capital theory to prove the ability to create useful competitions between companies by means of developing individual human resources. Therefore, in the present research, after studying more than 100 papers, the role of human capital in the organization and the characteristics of human capital have been studied. The results indicate that the common index, which is important at all levels of management in the organization, is human skill. Those who work in the central core of the organization must develop higher skills. These people must have enough knowledge, information, innovation, and creativity to increase the customer's satisfaction and create competitive advantage for the organization
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