Loading...
Search for: amino-acids
0.008 seconds
Total 140 records

    Application of Cellulose Nanofibers Coated Quartz Crystal Microbalance (QCM)Biosensor for Amino Acid Detection in Aqueous Media

    , Ph.D. Dissertation Sharif University of Technology Hosseini, Marzieh Sadat (Author) ; Iraji Zad, Azam (Supervisor) ; Vossoughi, Manouchehr (Supervisor)
    Abstract
    Developing a simple, cost effective and accurate detection method for L-lysine (Lys), L-leucine (Leu) and glycine (Gly) as the important analytes in clinical diagnostics, biological processes and food industries is of great interest. Therefore, in the first part of this research, cellulose nanofibrils (CNFs) were coated on a quartz crystal microbalance (QCM) surface by spin coating to achieve a QCM biodetector for Gly. Thus, the two-layer CNFs coating was selected as sensing film and was applied for following experiments. In the next step, the coated QCMs were carefully characterized before and after interaction with Gly using water contact angle (WCA), Fourier transform infrared... 

    Application of Cellulose Nanofibers Coated Quartz Crystal Microbalance (QCM) Biosensor for Amino Acid Detection in Aqueous Media

    , Ph.D. Dissertation Sharif University of Technology Hosseini, Marzieh Sadat (Author) ; Irajizad, Azam (Supervisor) ; Vossoughi, Manouchehr (Supervisor)
    Abstract
    Developing a simple, cost effective and accurate detection method for L-lysine (Lys), L-leucine (Leu) and glycine (Gly) as the important analytes in clinical diagnostics, biological processes and food industries is of great interest. Therefore, in the first part of this research, cellulose nanofibrils (CNFs) were coated on a quartz crystal microbalance (QCM) surface by spin coating to achieve a QCM biodetector for Gly. Thus, the two-layer CNFs coating was selected as sensing film and was applied for following experiments. In the next step, the coated QCMs were carefully characterized before and after interaction with Gly using water contact angle (WCA), Fourier transform infrared... 

    Gold Electroless from Sulfite-thiosulfate Bath

    , M.Sc. Thesis Sharif University of Technology Jahanianfar, Hooman (Author) ; Dolati, Abolghasem (Supervisor)
    Abstract
    Gold coatings due to their unique properties, use in a wide range of applications.Decorative coatings of gold for centuries, has been considered.However, few studies have been done on the properties of this metal, this metal is shown not only in terms of decorating, but in the industry also has a wide range of applications. In this project non-cyanide electroless bath based on binary complex sulfite-thiosulfate was prepared and metal ion concentration of the complex components, temperature, time, pH and addition of amino acids, optimzed bystability, qualityand rate of coating. The main aim of optimizing bathsis optimize the thickness and appearance of the coating.It was found that by... 

    Expremental Studying and Thermodynamic Modeling of Separation of Amino Acids by Ionic Liquids

    , M.Sc. Thesis Sharif University of Technology Nazem, Hadi (Author) ; Ghotbi, Cyrus (Supervisor) ; Taghikhani, Vahid (Supervisor) ; Vosoghi, Manochehr (Supervisor)
    Abstract
    In this work, partitioning of amino acids such as glutamic acid, phenyl anine and tryptophan in aqueous and ionic liquid phases at 298.15 K and atmospheric pressure was measured. [C4mim][Tf2N] is used due can produce two phase with water rapidly. Studying the effect of liquid solution pH on amino acids partitioning shows that increasing of pH results in decreasing of amino acid partitioning coefficient. This phenomenon pertains to electrostatic interactions between cation of amino acid and anion of ionic liquid which reduces when pH increases. Considering the effect of pH, liquid-liquid equilibrium data of amino acids was obtained in a pH that owning maximum partioning coefficient. Chemical... 

    Design of Drug Structures in Order to Inhibit Met, A Member of the Tyrosine Phosphatase Protein Family to Replace Existing Drugs

    , M.Sc. Thesis Sharif University of Technology Zeinal, Mostafa (Author) ; Fattahi, Alireza (Supervisor)
    Abstract
    This project aims to design a novel structure that can inhibit the activitvation of the c-Met enzyme using amino acids and sugars building blocks. The c-Met enzyme is a receptor tyrosine kinase that plays a significant role in several biological activities such as cell proliferation, survival, and invasion. Abnormal activity of the enzyme is linked to the progression of various types of cancer, including breast, lung, liver, and stomach cancer. The proposed sugar amino acid conjugate structures is expected to increase stability amino acids and dipeptides in the physiological environment, improve membrane permeability via active transport mechanism, and reduce toxicity and side effects by... 

    Design and Computational Evaluation of Sugar-Amino Acid Conjugates as CK2α Inhibitor

    , M.Sc. Thesis Sharif University of Technology Nonanal Nahr, Milad (Author) ; Fattahi, Alireza (Supervisor)
    Abstract
    The aim of this study is to devise innovative compounds that impede the function of CK2α enzyme by incorporating amino acids and sugars into their molecular structure. CK2α, a catalytic subunit of CK2 enzyme, operates autonomously and is the only continuously active kinase that does not require an upstream regulator. Emerging evidence highlights CK2α's crucial role in various cancers and infectious diseases, including Covid-19, indicating that suppressing its function could provide a promising approach to improve patient outcomes. To accomplish this objective, the drug design process must take into account both pharmacokinetic and pharmacodynamic properties. Pharmacokinetics, encompassing... 

    Design of Methods for Synthesis and Immobilization of Nitrogen Ligands Such as Pyridine onto the Mesoporous Silica Nanoparticles and Design of Pharmaceutical Structures Based on Amino Acids and Carbohydrates to Inhibit Polymerase Η for the Treatment of Leukemia and their Applications In Resins and Ionic Liquids

    , Ph.D. Dissertation Sharif University of Technology Kalhor, Sepideh (Author) ; Matloubi Moghaddam, Firouz (Supervisor) ; Fattahi, Alireza (Supervisor)
    Abstract
    1- Mesoporous silica materials have been found to possess pore sizes ranging from 2 -10 nm alongside 2D-hexagonal and 3D-cubic structural features. The specific properties of nanoparticles of the mesoporous silica family, such as the collected size, porosity, morphology, and high chemical stability, make them among the best drug delivery systems and catalysts. Designing the catalysts with advanced structures that effectively locate the transition metals and create active centres onto the surfaces of mesoporous silica materials has attracted extraordinary attention. According to many studies, mesoporous silica materials without organic functional groups cannot be used as catalysts in chemical... 

    Synthesis and Study of the Interaction of Aza-Crwon Macrocyclic Ligands with Carboxylate Side Arms with Cd Salts

    , M.Sc. Thesis Sharif University of Technology Mohammadzadeh, Amir Hossein (Author) ; Ghanbari, Bahram (Supervisor)
    Abstract
    In the present study, the coordination chemistry of an amino acid azacrown macrocycle ligand bearing one carboxylic acid arm (MA1) was investigated by employing NMR spectroscopy, crystallography and computational chemistry. MA1 was synthetized by the reaction of chloroacetic acid with the parent azacrown macrocycle and its purity was confirmed with 13C and 1H NMR for the first time. A new MA1 homologue, MA3 was also successfully prepared and characterized with NMR, mass spectrometry, and elemental analysis. NMR studies showed that MA1 binds to cadmium via the carboxylate arm in solution. Crystallographic studies showed that MA1 formed a one-dimensional polymer with cadmium, wherein the... 

    Design a New Sugar- amino Acid-based Drug Structure as an Alternative to Methotrexate, with the Aim of Treating Leukemia and some Autoimmune Diseases

    , M.Sc. Thesis Sharif University of Technology Shapouri, Amin Mohammad (Author) ; Fattahi, Alireza (Supervisor)
    Abstract
    This project aims to design a drug to fight leukemia and some autoimmune diseases having few side effects. These drugs are composed of natural sugar and amino acid structures. Among the various treatments available, drug structures as inhibitors of enzymes involved in cancer-related cellular processes is an important treatment. Methotrexate is one of the most widely used anticancer drugs in the last half-century and treats leukemia and many autoimmune diseases such as psoriasis. It is a derivative of folic acid (vitamin B9) and one of the drugs with specific properties. It is an anti-folate whose anti-metabolic effects can help kill cancer cells. One of the problems with using this drug to... 

    Preparation of Thin-Film Nanocomposite Membranes Based on Metal-Organic Frameworks (Mofs) and Study of their Performance in Forward Osmosis (Fo) Process

    , Ph.D. Dissertation Sharif University of Technology Bayrami, Arshad (Author) ; Bagherzadeh, Mojtaba (Supervisor)
    Abstract
    The forward osmosis (FO) process is a high potential emerging membrane process in the seawater desalination and contaminated water treatment fields. One of the main challenges facing this process is the weak separation (high reverse solute flux, low water flux, and insufficient selectivity) and antifouling performances of its membranes. Various sections of this study focus on the development of FO membranes and their performance improvement. For this purpose, thin-film composite membranes with the same combination of polyethersulfone/polyamide (PES/PA) have been used to investigate the effect of metal-organic frameworks (MOFs) introduction on their performance. The support layer in all cases... 

    Computational Design of Novel Medicines as Inhibitors in Case of Cancer and Autoimmune Disease Treatment Based on Amino Acid and Sugar

    , M.Sc. Thesis Sharif University of Technology Feghhi, Razieh (Author) ; Fattahi, Alireza (Supervisor)
    Abstract
    SHP2 has been reported as a critical non-receptor phosphatase enzyme that plays crucial roles in numerous disorders like cancer. The previous studies on this enzyme showed that inhibiting the action of the enzyme comes as a way of controlling enzyme activity. SHP099 was discovered as an Allosteric inhibitor of the enzyme with the most inhibitory effect among all of the studied compounds. In this study we aimed to design novel dipeptide-and sugar-based inhibitors for the allosteric binding site of this enzyme with in-silico studies including docking, molecular dynamic simulation, and free binding energy analysis. Our novel designed drugs possess enough binding properties, low toxicity, and... 

    Expression and Purification of Amyloid Beta Recombinant Peptide and the Effecs of Ultrasmall Peptides Enriched in Branch Chain Amino Acids as Inhibitors in Amyloid Formation

    , M.Sc. Thesis Sharif University of Technology Rezaei Adariani, Soheila (Author) ; Kalhor, Hamid Reza (Supervisor)
    Abstract
    Nowdays, it has been shown that protein misfolding is involved in more than forty diseases including Alzheimer’s and Parkinson’s. Alzheimer’s disease is one of the most common neurodegenerative diseases that disrupts brain function. The main cause of this illness is due to formation of extracellular amyloid plaque from a 42-amino acid-peptide called amyloid beta. Amyloidosis is caused by missfolding of peptides and proteins mainly because of physical and chemical changes in biomolecule or their environment.
    Therefore, in this dissertation, using synthetic and recombinant abeta peptide, kinetic of amyloidosis was examined. Ultrasmall peptides (three-amino acid), containing branched chain... 

    , M.Sc. Thesis Sharif University of Technology GHasemi Toosi, Faeze (Author) ; Ghanbari, Bahram (Supervisor)
    Abstract
    The purpose of this project is the synthesis and characterization of a group of phenolic amino acidic derivatives that are studied in both solid phases as well as their solutions. For this, new phenol derivatives of serin and isoleucine amino acids were synthesized and characterized by 1H NMR , 13C NMR, IR spectroscopy as well as elemental analysis. These ligands were utilized to prepare LSF perovskite membrane. According to their XRD patterns, it was concluded that the powdered precursor prepared by serin derivative has shown better qualification and less intermediate phase in the synthesized perovskite membrane similar to the sample prepared by applying EDTA. Furthermore, in the previous... 

    , M.Sc. Thesis Sharif University of Technology Rahmani, Atefeh (Author) ; Gholami, Mohammad Reza (Supervisor)
    Abstract
    Nanosized CdS coupled TiO2 nanocrystals were prepared by a microemulsion-mediated Hydrothermal method at relatively low temperatures. Modification of this nanocomposite with Tyrosine,Phenylalanine,Glysine and Glutamate ,especially Tyrosine resulted in enhanced photocatalytic degradation rate of Nitrobenzene( NB ) compared to using CdS-TiO2 under visible light irradiation. The prepared samples were characterized by BET,SEM, XRD, UV–Vis spectroscopy ,FTIR .It was found which have high surface area about 470 m2 g−1 and mesoporous character with the average pore diameter of 2.8 nm.The results showed this nanocomposite consisted of uniform anatase TiO2 with highly dispersed cubic phase CdS... 

    Synthesis and Application of Aminophenolic Ligands in Preparation of Perovskite-type Inorganic Membranes

    , M.Sc. Thesis Sharif University of Technology Hajibabaei Najafabadi, Hamed (Author) ; Ghanbari, Bahram (Supervisor)
    Abstract
    Inorganic membranes are a group of compounds which are used in gas separations such as isolating of oxygen from air and/or in petrochemical process like OCM, POM. These days, a variety of research is being conducted to synthesize these membranes from perovskite structures with formulation of ABO3. These compounds have various production procedures and various final perovskite compounds. The purpose of this project is to synthesis and identification of a group of phenolic amino acidic derivatives as new chelating agents, and their use in synthesis of perovskite membranes. For this, novel phenol derivatives of glycine, alanine, β- alanine and leucine amino acids were synthesized and... 

    Synthesis of Amino Acids Schiff Base Complexes of Gadolinium and Study of Their Interaction with BSA

    , M.Sc. Thesis Sharif University of Technology Abedi, Najmeh (Author) ; Mohammadi Boghaei, Davar (Supervisor)
    Abstract
    Salicylaldehyde-amino acid Schiff base complexes are used as non-enzymatic models for the metal-pyridoxal (Vitamin B6) amino acid Schiff base systems which are key intermediates in many metabolic reactions of amino acids catalyzed by enzymes which require pyridoxal as a cofactor (transamination, decarboxylation, α and β elimination, racemization, etc.). In addition, complexes of amino acid Schiff bases are considered to constitute new kinds of potential anticancer, antitumor, antiradical and antibacterial reagents. On the other hand nuclear magnetic resonance imaging (MRI), has become a powerful tool for clinical diagnostics thanks to the development of a new class of pharmaceuticals... 

    Dependency of codon usage on protein sequence patterns: A statistical study

    , Article Theoretical Biology and Medical Modelling ; Vol. 11, issue. 1 , 2014 ; ISSN: 17424682 Foroughmand-Araabi, M. H ; Goliaei, B ; Alishahi, K ; Sadeghi, M ; Sharif University of Technology
    Abstract
    Background: Codon degeneracy and codon usage by organisms is an interesting and challenging problem. Researchers demonstrated the relation between codon usage and various functions or properties of genes and proteins, such as gene regulation, translation rate, translation efficiency, mRNA stability, splicing, and protein domains. Researchers usually represent segments of proteins responsible for specific functions or structures in a family of proteins as sequence patterns or motifs. We asked the question if organisms use the same codons in pattern segments as compared to the rest of the sequence. Methods. We used the likelihood ratio test, Pearson's chi-squared test, and mutual information... 

    Amino acids and their complex formation properties with divalent metal ions, a comparative investigation of structure and stability in binary systems

    , Article Current Pharmaceutical Analysis ; Volume 10, Issue 2 , 2014 , Pages 122-134 ; ISSN: 15734129 Sajadi, S. A. A ; Sharif University of Technology
    Abstract
    A comparative investigation has been developed for the stability constants of several amino acid complexes with divalent metal ions, which have been determined by potentiometric pH titration. Depending on the metal ion-binding properties, vital differences in the building complexes were observed. The present study indicates that in some M(L) complexes, metal ions are arranged in carboxyl groups, but in other M(L)complexes, some metal ions are able to build chelate over amine groups. The results mentioned-above demonstrate that for some M(L) complexes, the stability constants are also largely determined by the affinity of metal ions for amine group. This leads to a kind of selectivity of... 

    Stability of binary and ternary copper (II) complexes of 2((4-methyl-5-nitro-6-(pyrrolidine-l-yl)pyrimidine-2-yl) amino) propionic acid in aqueous solution

    , Article Scientia Iranica ; Vol. 21, Issue. 6 , 2014 , pp. 2029-2035 ; ISSN: 10263098 Sajadi, S. A. A ; Bagherzadeh, G ; Khaleghian, M ; Kermani, M ; Sharif University of Technology
    Abstract
    The acidity and stability constants of M (MNPPAP) (MNPPAP: 2((4-methyl-5-nitro-6-(pyrrolidine-l-yl)pyrimidine-2-yl)amino)propionic acid) M: Cu2+, Cu (Bpy)2+ (Bpy: 2,2'-Bipyridine), or Cu(Phen) (Phen: 1,10-Phenanthroline) complexes were determined by potentiometric pH titration. It is shown that the stability of the binary Cu (MNPPAP) complex is determined by the basicity of the carboxylate group on one side and amine group on the other side. It is demonstrated that the equilibrium, Cu(Har)2+ (H ar: Heteroaromatic ligand such as Bpy or Phen) + Cu(MNPPAP) ^ Cu(Har)(MNPPAP) + Cu2+, is displacement due to the well known experience that mixed ligand complexes formed by a divalent 3d ion, a... 

    Rapid and simultaneous determination of tetracycline and cefixime antibiotics by mean of gold nanoparticles-screen printed gold electrode and chemometrics tools

    , Article Measurement: Journal of the International Measurement Confederation ; Vol. 47, Issue. 1 , 2014 , pp. 145-149 ; ISSN: 02632241 Asadollahi-Baboli, M ; Mani-Varnosfaderani, A ; Sharif University of Technology
    Abstract
    The screen-printed gold electrode (SPGE) modified with the formation of self-assembly monolayer (SAM) of cysteine (Cys) on gold-nanoparticles (Au nano) was utilized for rapid and simultaneous determination of tetracycline and cefixime antibiotics by square wave voltammetry (SWV). Electrochemical investigation and characterization of the modified electrode was achieved using cyclic voltammetry (CV) and scanning electron microscopy (SEM). A principal component artificial neural network (PCANN) with three layer back-propagation network was utilized for the analysis of the voltammogram data. It is possible to simultaneously determine the tetracycline and cefixime concentrations in the ranges of...