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nuclear-magnetic-resonance-spectroscopy
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Simultaneous determination of theophylline and caffeine by proton magnetic resonance spectroscopy using partial least squares regression techniques
, Article Analytical Sciences ; Volume 19, Issue 7 , 2003 , Pages 1079-1082 ; 09106340 (ISSN) ; Maesum, S ; Jalali Heravi, M ; Shamsipur, M ; Sharif University of Technology
Japan Society for Analytical Chemistry
2003
Abstract
A 1H-NMR procedure based on an analysis of its data by a multivariate calibration method was conducted for the simultaneous determination of theophylline and caffeine in synthetic and real samples. Partial least squares regression (PLS) was chosen as the calibration method. The methyl signals of theophilline at 3.36 and 3.54 ppm that overlapped with those of caffeine were significant characteristics which were employed in this study for their analyses. The proposed method was successfully applied to recovery studies of theophylline and caffeine from real tablet samples
The Differential Diagnosis of Crohn's Disease and Celiac Disease Using Nuclear Magnetic Resonance Spectroscopy
, Article Applied Magnetic Resonance ; Volume 45, Issue 5 , May , 2014 , Pages 451-459 ; Kasmaee, L. M ; Sohrabzadeh, K ; Nejad, M. R ; Tafazzoli, M ; Oskouie, A. A ; Sharif University of Technology
Abstract
Crohn's disease and celiac disease belong to a group of autoimmune conditions that affect the digestive system, specifically the small intestine. They both attack the digestive tract and share many symptoms. Thus, the discovery of proper methods would be a major step toward differentiating celiac disease from Crohn's disease. The aim of this study was to search for the metabolic biomarkers to differentiate between these two diseases. Proton nuclear magnetic resonance spectroscopy (1H NMR) was employed as the metabolic profiling method to look for serum metabolites that differentiate between celiac disease and Crohn's disease. Classification of celiac disease and Crohn's disease was done...
Relationship between serum level of selenium and metabolites using 1hnmr-based metabonomics in parkinson's disease
, Article Applied Magnetic Resonance ; Volume 44, Issue 6 , January , 2013 , Pages 721-734 ; 09379347 (ISSN) ; Kyani, A ; Darvizeh, F ; Mehrpour, M ; Tafazzoli, M ; Shahidi, G ; Sharif University of Technology
2013
Abstract
Parkinson's disease (PD) is a neurodegenerative disease, which is not easily diagnosed using clinical tests and the discovery of proper methods would be a major step towards a successful diagnosis. In the present study, we employed metabolic profiling using proton nuclear magnetic resonance spectroscopy to find metabolites in serum, which are helpful for the diagnosis of PD. Classification of PD and healthy subject was done using random forest. Serum levels of selenium measured by atomic absorption spectrometry in PD group were lower than the serum selenium levels in the control group. The metabolites causing selenium changes in PD patients were identified using random forest, and a model...
Reactivity of a new aryl cycloplatinated(ii) complex containing rollover 2,2′-bipyridine: N -oxide toward a series of diphosphine ligands
, Article New Journal of Chemistry ; Volume 42, Issue 11 , 2018 , Pages 9159-9167 ; 11440546 (ISSN) ; Babadi Aghakhanpour, R ; Hossein Abadi, M ; Kia, R ; Halvagar, M. R ; Raithby, P. R ; Sharif University of Technology
Abstract
Reaction of the electron-rich complex cis-[Pt(p-Me-C6H4)2(SMe2)2] with 2,2′-bipyridine N-oxide, O-bpy occurred by rollover cyclometalation to afford complex [Pt(O-bpy)(p-Me-C6H4)(SMe2)], 1. The obtained complex was characterized using NMR spectroscopy and its solid state structure was determined by the single crystal X-ray diffraction method. The reaction of 1 with seven diphosphine ligands, 1,1-bis(diphenylphosphino)methane (dppm), 1,2-bis(diphenylphosphino)ethane (dppe), 1,3-bis(diphenylphosphino)propane (dppp), 1,4-bis(diphenylphosphino)butane (dppb), N,N-bis(diphenylphosphino)amine (dppa), 1,2-bis(diphenylphosphino)benzene (dppbz) and 1,1′-bis(diphenylphosphino)ferrocene (dppf), in...
Synthesis of novel water-soluble aminodeoxychitin derivatives
, Article Starch/Staerke ; Volume 59, Issue 11 , 2007 , Pages 557-562 ; 00389056 (ISSN) ; Seidi, F ; Salimi, H ; Sharif University of Technology
2007
Abstract
Eight new chitin derivatives have been synthesized via SN2 reaction of primary and secondary amines with tosylchitin. The products were characterized using FTIR and 1H NMR spectroscopy. A degree of substitution ∼ 1 was achieved through this process. These materials are soluble in water at room temperature, which enable their further applications in the future. © 2007 WILEY-VCH Verlag GmbH & Co. KGaA
Synthetic study of symmetrical and unsymmetrical schiff base complexes of VO(IV) and Mn(III) derived from 2,2′-diaminobiphenyl
, Article Synthesis and Reactivity in Inorganic, Metal-Organic and Nano-Metal Chemistry ; Volume 35, Issue 4 , 2005 , Pages 261-267 ; 15533174 (ISSN) ; Behzad, M ; Sharif University of Technology
2005
Abstract
The symmetrical and unsymmetrical Schiff base complexes of VO(IV) and Mn(III) derived from 2,2′-diaminobiphenyl and derivatives of salicylaldehyde and 1-hydroxy-2-napnthaldehyde have been synthesized and characterized by elemental analysis, NMR, infrared and electronic absorption spectroscopies, and conductivity measurements. The reaction of the ligands with oxovanadium(IV) was found to be kinetically unfavored, probably due to the small ionic radius of the metal ion, which is not in accordance with the cavity size of the ligands. Copyright © 2005 Taylor & Francis, Inc
The feasibility Study on Magnetic Resonance Spectroscopy (MRS) Thermometry in the Presence of Magnetic Field Inhomogeneity
, M.Sc. Thesis Sharif University of Technology ; Samadfam, Mohammad (Supervisor) ; Saligheh Rad, Hamid Reza (Supervisor)
Abstract
1H-MRS thermometry as one of MRI thermometry methods, provides useful information about the distribution of the absolute temperature of tissue that can be used in diagnostic and therapeutic applications. It seems that the magnetic field inhomogeneity and the reduction of spectra resolution also affects the accuracy of MRS thermometry. To our knowledge, effects of magnetic field inhomogeneity on MRS thermometry has never been reported. In this study, we evaluated the effect of susceptibility inhomogeneity on MRS thermometry. In the first stage, MRS thermometry equation was derived in the presence of field inhomogeneity. Then simulation used for estimate the effect of filed inhomogeneity based...
The Pattern Recognition Methods in Combination with Nuclear Magnetic Resonance (NMR)Spectroscopy in Order to Develop a Metabolomic Approach to Breast Cancer Prognosis
, M.Sc. Thesis Sharif University of Technology ; Parastar Shahri, Hadi (Supervisor)
Abstract
The emerging field of “metabolomics” focuses on investigating into the changes of low-molecular-weight – less than 1500 Daltons – molecules, or metabolites, and it has significantly developed in the field of detecting diseases, particularly cancer in recent years. Regarding the importance of breast cancer (BC), especially among women, developing simple, trusted metabolic approaches are crucial. In the present work, utilizing multivariate class-modelling techniques combined to nuclear magnetic resonance (NMR) in order to predict breast cancer based on analyzing the blood serum of healthy and BC patients is presented. To do so, using 42 blood samples, 18 BC patients and 24 healthy individuals,...
Synthesis and characterization of a new group of Exo-coordinating o2n2-donor macrocycles
, Article Australian Journal of Chemistry ; Volume 69, Issue 3 , 2016 , Pages 273-278 ; 00049425 (ISSN) ; Safarkoopayeh, B ; Kia, R ; Raithby, P.R ; Sharif University of Technology
CSIRO
2016
Abstract
The reaction of 15-18 membered benzodiazacrown ethers with salicylaldehyde afforded n-membered O2N2-donor macrocyclic ligands mounted with 1,3-diazacyclohexane subrings (1-4) in high yields. The products were characterized by FT-IR, 1H, 13C NMR spectroscopy, elemental analyses, and single crystal X-ray studies. The solid state structures revealed strong intramolecular hydrogen bonding between the pendant phenolic group and the tertiary nitrogen of the corresponding macroring
Structure and conformation of α-, β- and γ-cyclodextrin in solution: theoretical approaches and experimental validation
, Article Carbohydrate Polymers ; Volume 78, Issue 1 , 2009 , Pages 10-15 ; 01448617 (ISSN) ; Ghiasi, M ; Sharif University of Technology
2009
Abstract
The anomeric carbon chemical shifts of α-, β- and γ-cyclodextrin in solution were studied experimentally and theoretically by NMR and two-layer ONIOM2 (B3LYP/6-31G*-GIAO: HF/6-31G*-GIAO) variant. The dependence between the anomeric carbon chemical shift and the glycosidic bond φ and ψ dihedral angles in d-Glcp-d-Glcp disaccharides with and (1 → 4) linkages in α-configurations were computed by Gauge-Including Atomic Orbital (GIAO) ab initio and ONIOM in water solvent using PCM methods. Complete chemical shift surfaces versus φ and ψ for this disaccharide were computed. We also present empirical formulas of the form 13C δ = f(φ, ψ) obtained by fitting the ab initio data to trigonometric series...
Improving the performance of speech recognition systems using fault-tolerant techniques
, Article 2008 9th International Conference on Signal Processing, ICSP 2008, Beijing, 26 October 2008 through 29 October 2008 ; 2008 , Pages 579-582 ; 9781424421794 (ISBN) ; Sameti, H ; Sharif University of Technology
2008
Abstract
In this paper, using of fault tolerant techniques are studied and experimented in speech recognition systems to make these systems robust to noise. Recognizer redundancy is implemented to utilize the strengths of several recognition methods that each one has acceptable performance in a specific condition. Duplication-with-comparison and NMR methods are experimented with majority and plurality voting on a telephony Persian speech-enabled IVR system. Results of evaluations present two promising outcomes, first, it improves the performance considerably; second, it enables us to detect the outputs with low confidence. © 2008 IEEE
Partially aromatic polyamides based on tetraphenylthiophene diamine: synthesis and characterization
, Article Journal of Applied Polymer Science, New York, NY, United States ; Volume 77, Issue 5 , 2000 , Pages 1144-1153 ; 00218995 (ISSN) ; Zamanlu, M. R ; Zohuriaan Mehr, M. J ; Sharif University of Technology
John Wiley & Sons Inc
2000
Abstract
Tetraphenylthiophene diamine (TPTDA) was prepared through a modified three-step route to achieve an improved overall yield. TPTDA reacted with succinic, adipic, suberic, sebasic, and fumaric acids via the Yamazaki phosphorylation method to yield novel partially aromatic polyamides (TPT series). A counterpart polyamide series based on p-phenylene diamine (Ph series) was also synthesized under the same conditions. All of the polymers were characterized by means of spectrochemical (Fourier transform infrared spectroscopy. 1H-nuclear magnetic resonance (NMR), and 13C-NMR) and thermal (differential scanning calorimetry and thermogravimetric) methods of analysis. Solubility of TPT polyamides was...
Experimental investigation of poly-β-hydroxybutyrate production by azohydromonas lata: Kinetics and artificial neural network modeling
, Article Chemical Engineering Communications ; Volume 203, Issue 2 , 2016 , Pages 224-235 ; 00986445 (ISSN) ; Younesi, H ; Ardjmand, M ; Safe Kordi, A ; Yaghmaei, S ; Qaderi, H ; Sharif University of Technology
Taylor and Francis Ltd
2016
Abstract
Batch culture of Azohydromonas lata was investigated for the production of intracellular poly-b-hydroxybutyrate (PHB). In order to determine the C:N value of the culture media for maximizing the microbial productivity of PHB, different concentrations of glucose and ammonium chloride were used as carbon and nitrogen sources, respectively. The optimal temperature and shaking rate was obtained at 30_C and 180 rpm, respectively. The maximum intracellular PHB concentration obtained was 5.09 g/l, which was 20% (w/w) of the cell dry weight (CDW) after 72 h. Also, the synthesis of PHB was growth associated with the C:N ratio of 153.71. The maximum calculated Yp/s was 0.212 (gr/gr) and the specific...
Spectrophotometric Study of Formation of Donor-Acceptor Adducts of Selenium Dioxide with Amines and Pyridine like Bases
, M.Sc. Thesis Sharif University of Technology ; Mohammadi Boghaei, Davar (Supervisor)
Abstract
Donor-acceptor adducts of selenium dioxide were formed with tree aromatic amines, two aliphatic amines and tree pyridine like bases. Characterization of these adducts were done through UV-Vis Spectrophotometer and IR Spectrophotometer and NMR Spectroscopy. In addition, the stoichiometry of these adducts were identified by elemental analysis (CHN). To approve the existence of selenium, Atomic absorption instrument was used.The results obtained from the entioned methods show that the adduct formation between selenium dioxide with amines and pyridine like bases are in following order: p-phenylen diamine.SeO2>NH5.SeO2,en.SeO2,cyclohexylamine.SeO2,...
Structural Study of Vitamin B1, B2 and B6 by NMR Spectroscopy and ab-initio Methods
, M.Sc. Thesis Sharif University of Technology ; Tafazzoli, Mohsen (Supervisor)
Abstract
The structure and energy of vitamin B1 (Thiamine), vitamin B2 (Riboflavin) and vitamin B6 (Pyridoxine) have been studied employing quantum mechanical calculation, DFT methods at B3LYP level using 6-311+G* basis set. Values of the coupling constants involving carbon-hydrogen and hydrogen-hydrogen on the torsion angle α and β were theoretically calculated. All Karplus equations which represent the correlation between coupling constants 1JCH, 2JHH, 2JCH, 3JHH, 3JCH and proper dihedral angle have been yielded. The effect of three solvents, water, ethanol and carbon¬ tetrachloride with different polarity on coupling constants, energy and structural parameters were calculated employing PCM model....
Experimental and theoretical study of the spectroscopic properties and the preparation of 3-benzyl-2H-pyrano[3,2-c]chromene-2,5(6H)-dione
, Article Journal of Molecular Structure ; Vol. 1065-1066, issue. 1 , May , 2014 , pp. 235-240 ; ISSN: 00222860 ; Foroushani, B. K ; Sharif University of Technology
Abstract
Compound 3-benzyl-2H-pyrano[3,2-c]chromene-2,5(6H)-dione(3), was prepared and fully characterized. The vibrational modes (FT-IR) and NMR data ( 1H and 13C chemical shifts) were compared with the results of Density Functional Theory (DFT) method at the B3LYP/cc-PVTZ level. The calculated vibrational frequencies and NMR chemical shifts are in good agreement with the experimental results. The electronic (UV-Vis) spectrum was calculated using the TD-DFT method in CH2Cl2 with the Polarizable Continuum Model using the integral equation formalism variant (IEFPCM) and was correlated to the experimental spectra. The assignment and analysis of the frontier HOMO and LUMO orbitals indicate that...
A metabonomics investigation of multiple sclerosis by nuclear magnetic resonance
, Article Magnetic Resonance in Chemistry ; Volume 51, Issue 2 , DEC , 2013 , Pages 102-109 ; 07491581 (ISSN) ; Kyani, A ; Tafazzoli, M ; Fathi, F ; Joghataie, M. T ; Sharif University of Technology
2013
Abstract
Multiple sclerosis (MS) is a nervous system disease that affects the fatty myelin sheaths around the axons of the brain and spinal cord, leading to demyelination and a broad range of signs and symptoms. MS can be difficult to diagnose because its signs and symptoms may be similar to other medical problems. To find out which metabolites in serum are effective for the diagnosis of MS, we utilized metabolic profiling using proton nuclear magnetic resonance spectroscopy (1H-NMR). Random forest (RF) was used to classify the MS patients and healthy subjects. Atomic absorption spectroscopy was used to measure the serum levels of selenium. The results showed that the levels of selenium were lower in...
Synthesis, structure and photophysical properties of binuclear methylplatinum complexes containing cyclometalating 2-phenylpyridine or benzo{h}quinoline ligands: A comparison of intramolecular Pt-Pt and π-π Interactions
, Article Dalton Transactions ; Volume 40, Issue 36 , 2011 , Pages 9123-9130 ; 14779226 (ISSN) ; Czerwieniec, R ; Kia, R ; Jamshidi, Z ; Zabel, M ; Sharif University of Technology
2011
Abstract
The binuclear cyclometalated complexes [Pt2Me 2(ppy)2(μ-dppm)], 1a, and [Pt2Me 2(bhq)2(μ-dppm)], 1b, in which ppy = 2-phenylpyridyl, bhq = benzo{h}quinoline and dppm = bis(diphenylphosphino)methane, were synthesized by the reaction of [PtMe(SMe2)(ppy)] or [PtMe(SMe 2)(bhq)] with 1/2 equiv of dppm at room temperature, respectively. Complexes 1a and 1b were fully characterized by multinuclear (1H, 31P, 13C, and 195Pt) NMR spectroscopy and were further identified by single crystal X-ray structure determination. A comparison of the intramolecular Pt-Pt and π-π interactions in complexes 1a and 1b has been made on the basis of data on crystal structures and wave functions analysis. The binuclear...
Synthesis of a new T-shaped heterobinuclear Pt0-AuI complex [(t-Bu3P)2PtAu(PPh3)]BF4 from trinuclear gold cluster complex [(PPh3)Au]3(μ-O)BF4
, Article Scientia Iranica ; Volume 23, Issue 3 , 2016 , Pages 1089-1094 ; 10263098 (ISSN) ; Ashtiania, M. M ; Milic, D ; Sharif University of Technology
Sharif University of Technology
2016
Abstract
The heterobinuclear platinum(0)-gold(I) complex [(t-Bu3P)2PtAu(PPh3)] BF4, 5, was synthesized by the reaction of trinuclear cluster complex f[(PPh3)Au]3(μ-O)gBF4, 4, with one equiv of [(t-Bu3P)2Pt] at room temperature. The heterobinuclear complex 5 was characterized using multinuclear NMR spectroscopy and elemental microanalysis and was further identified by single crystal X-ray structure determination. Crystal structure of 5 shows a T-shaped geometry with an unsupported short distance Pt-Au dative bond
Conformation of repaglinide: a solvent dependent structure
, Article Journal of Molecular Structure ; Volume 1143 , 2017 , Pages 388-396 ; 00222860 (ISSN) ; Tafazzoli, M ; Sharif University of Technology
Abstract
Experimental and theoretical conformational study of repaglinide in chloroform and dimethyl sulfoxide was investigated. By applying potential energy scanning (PES) at B3LYP/6-311++g** and B3LYP-D3/6-311++g** level of theory on rotatable single bonds, four stable conformers (R1-R4) were identified. Spin-spin coupling constant values were obtained from a set of 2D NMR spectra (H[sbnd]H COSY, H[sbnd]C HMQC and H[sbnd]C HMBC) and compared to its calculated values. Interestingly, from 1HNMR and 2D-NOESY NMR, it has been found that repaglinide structure is folded in CDCl3 and cause all single bonds to rotate at an extremely slow rate. On the other hand, in DMSO-d6, with strong solvent-solute...