bluuebunny/crossref_metadata_2025 huggingface dataset:
Infrared microspectroscopic imaging as a probing tool to fast distinguish chemical compositions in calcified deposits of prostatic calculi and calcific tendonitis
Authors: Lin Shan-Yang , Wu Tieh-Kang , Chiou Hong-Jen , Hsu Ted Hueih-Shing , Lin Chih-Cheng
Published: April 2012

The specificity and homogeneity of the real compositional components within the calcified deposits of prostatic calculi and calcific tendonitis were investigated using Fourier transform infrared (FT-IR) microspectroscopy with or without automatic imaging system. The second-derivative analysis was also applied to differentiate the overlapping components of individual spectra for the calcified samples. The FT-IR microscopic imaging results of present study indicate that the complicated components such as protein, type B or type A carbonated apatite, brushite and calcium oxalate monohydrate were contained in the calcified tissue of prostatic tissue, but the protein, type A and type B carbonated apatites were mainly included in the calcific tendonitis. However, the traditional manually single-point FT-IR spectral result only reveals a little component contained in the calcified tissues, leading to an inaccurate diagnose of the complicated components in the calcified mixture.
Quantification of carbohydrates in fruit juices using FTIR spectroscopy and multivariate analysis
Authors: Leopold Loredana F. , Leopold Nicolae , Diehl Horst-A. , Socaciu Carmen
Published: April 2012

A combination of Fourier-transform infrared spectroscopy (FTIR) and multivariate statistics was applied as screening tool for the quantitative determination of carbohydrates, such as glucose, fructose and sucrose, in 28 processed commercial fruit juices and 5 genuine juices obtained from squeezed fruits. A number of 13 mixtures of glucose, fructose and sucrose standard solutions were prepared at different concentrations, scanned by attenuated total reflectance (ATR) FTIR spectroscopy and analyzed in the 900 and 1400 cm−1spectral range. Principal component analysis (PCA) of the standard carbohydrate solutions enabled a better understanding of the main sources of variability affecting the FTIR spectra. Also, PCA enabled the grouping of apple, orange and peach juices. Calibration models for each carbohydrate, using partial least squares (PLS) regression were developed and used for prediction purposes. Cross-validation procedures indicated correlations of 0.88, 0.92 and 0.98 for glucose, fructose and sucrose, respectively, between HPLC measured values and FTIR first derivative spectra estimates. Carbohydrates in the expected concentration ranges were found for most of the pure fruit labelled juices. The samples with 4–50% pure fruit juice content showed discrepancies from average concentration values of authentic juices, mainly a high sucrose concentration can flag sucrose addition to maintain the juice sweetness intensity. The present results confirmed the efficiency of FTIR spectroscopy, in combination with multivariate statistics, as a rapid, reliable and cost-effective tool for routine monitoring of multiple constituents in fruit juices, as quality indicators.
Subpicosecond dynamics in DNA from leaves ofin vitro-grown apple plants: A SERS study
Authors: Muntean Cristina M. , Bratu Ioan , Leopold Nicolae , Purcaru Monica A. P.
Published: April 2012

In this work the SERS total half bandwidths of five genomic DNAs fromin vitro-grown apple leaf tissues (Malus domesticaBorkh., FamRosaceae, cvs. Florina, Rebra, Goldrush, Romus 3 and Romus 4) have been measured. We have shown that surface-enhanced Raman scattering can be used to study the fast subpicosecond dynamics of DNA in the proximity of a metallic surface. The dependencies of the total half bandwidths and of the global relaxation times, on DNA molecular subgroup structure, on the type of genomic apple plant DNA and on time, are reported. An example of the time-dependence of SERS band parameters of DNA, in the proximity of silver nanoparticles, has been given. It is shown that changes in the subpicosecond surface dynamics of molecular subgroups in genomic DNAs fromin vitro-grown apple leaf tissues can be monitored with surface-enhanced Raman spectroscopy. Particularly, the SERS band parameters for the vibrations near 757 cm–1(dT), 773 cm–1(dC), 929 cm–1(deoxyribose), 1087 cm–1(PO2–symmetric stretch, backbone), 1127 cm–1(dA), 1181 cm–1(ring vibrations of dG, dT, dC), 1311 cm–1(dA), 1362 cm–1(dT, dA), 1510 cm–1(dA), 1573 cm–1(dG, dA) and 1650 cm–1[dT(C═O), δ(H2O)] of genomic DNAs from apple leaves are presented. In our study, the full widths at half-maximum (FWHM) of the bands in genomic DNAs fromin vitro-grown apple leaf tissues are typically in the wavenumber range from 14 to 52 cm–1. Besides, it can be observed that molecular relaxation processes studied in this work, have a global relaxation time smaller than 0.76 ps and larger than 0.20 ps. A comparison between different ranges of FT-Raman and SERS band parameters of DNA extracted from leaf tissues, respectively, is given. We have found that the bands of DNA from Romus 3 and Rebra cultivars are suitable for studying the dynamical behaviour of molecular subgroups, in genomic nucleic acids extracted fromin vitro-grown apple plants.
Synthesis, characterization and biological activities of cetirizine analogues
Authors: Sultana Najma , Arayne M. Saeed , Shamshad Hina , Mirza Agha Zeeshan , Naz Malik Asia , Fatima Beenish , Asif M. , Mesaik M. Ahmed
Published: April 2012

Cetirizine second generation H1-receptor antagonist is an acid metabolite of hydroxyzine. Present work was based on six new analogues of cetirizine having nucleophilic substitution reaction synthetic pathway. The reactions were proceeded by replacing the scaffold on the cetirizine moiety using nucleophilic substitution reaction. The structures of analogues were confirmed using UV, IR,1H NMR and mass spectroscopic techniques. The analogues were tested for the anti-inflammatory activities on cellular immune response. Oxidative burst response of phagocytes after exposure to the analogues was found to exhibit moderate to significant inhibitory activity (23 to <3.1). However, the compounds as MPC and PPC also showed remarkable inhibitory effect on PHA activated T-cells response and may prove to be lead compounds in therapeutic world.
Applications of vibrational spectroscopy in the study of flavin-based photoactive proteins
Authors: Li Jiang , Kitagawa Teizo
Published: April 2012

Flavin cofactor is known to perform diverse biological functions. Recently, its role as a photoreceptor has been identified. So far, three classes of photoactive flavoproteins have been recognized: phototropin with LOV (Light, Oxygen and Voltage) domain, blue light sensory protein with BLUF (Blue Light sensing Using Flavin adenine dinucleotide) domain and photolyase/cryptochrome protein with PHR (Photolyase Homology Region) domain. Photochemistry of flavin is the key to unravel the reaction mechanisms of photoactive flavoproteins in their biological functions such as DNA repair or signal transduction. Vibrational (Infrared and Raman) spectroscopy is a useful and sensitive tool to investigate the photochemistry of flavin in protein environments and has significantly contributed to elucidate the reaction mechanisms of these photoactive proteins. This study will survey recent advances in vibrational spectroscopic studies on this topic and remaining questions to be answered.
Electron paramagnetic resonance (EPR) study of DOPA–melanin complexes with kanamycin and copper(II) ions
Authors: Najder-Kozdrowska Lidia , Pilawa Barbara , Buszman Ewa , Wrzesniok Dorota , Więckowski Andrzej B.
Published: April 2012

This work comprises the study of DOPA–melanin complexes with kanamycin and copper(II) ions made by electron paramagnetic resonance EPR spectroscopy. The high concentration of paramagnetic centers in melanin makes the use of EPR spectroscopy possible. The unpaired electron localized on the oxygen atom in indol-5,6-quinone groups is the paramagnetic centers in this polymer. The aim of this work was the analysis of EPR parameters of recorded spectra. For researches were prepared melanin complexes which differed in complexing order of drug and Cu(II) ions, and in concentration of CuCl2solutions used during synthesis. The introduction of drugs and metal ions into melanin causes changes in EPR parameters of recorded spectra. Kanamycin causes the increase and copper(II) ions the decrease of concentrations of paramagnetic centres in melanin. Shape of EPR signal of DOPA–melanin was analyzed by fitting method. Results indicate that EPR line of DOPA–melanin is superposition of Gaussian and Lorentzian function.
Density functional theory study on the molecular structure of loganin
Authors: Pandey Anoop Kumar , Siddiqui Shamoon Ahmad , Dwivedi Apoorva , Raj Kanwal , Misra Neeraj
Published: April 2012

The computational Quantum Chemistry (QC) has been used for different types of problems, for example: structural biology, surface phenomena and liquid phase. In this paper we have employed the density functional method for the study of molecular structure of loganin. The equilibrium geometry, harmonic vibrational frequencies and infrared intensities were calculated by B3LYP/6-311G (d, p) method and basis set combinations. It was found that the optimized parameters obtained by the DFT/B3LYP method are very near to the experimental ones. A detailed conformational analysis was carried out. A detailed interpretation of the infrared spectra of loganin is also reported in the present work. The FT-IR spectra of loganin were recorded in solid phase. The thermodynamic calculations related to the title compound were also performed at B3LYP/6-311G (d, p) level of theory.
Surface-enhanced Raman and DFT study on zidovudine
Authors: Mircescu Nicoleta Elena , Varvescu Andrada , Herman Krisztian , Chiş Vasile , Leopold Nicolae
Published: April 2012

This work presents a surface-enhanced Raman scattering (SERS) and density functional theory (DFT) study on neutral and deprotonated molecular forms of zidovudine. A pKavalue of 9.55 was found for this compound, the deprotonation occurring at the imide nitrogen of the pyrimidine ring. The characteristic bands of the SERS spectra were assigned considering both, the calculated vibrational wavenumbers and Raman intensity pattern. The adsorption geometry on the silver surface of zidovudine was derived based on the molecular electrostatic potential (MEP) and the selective Raman bands enhancement.
UV-vis spectroscopic study of lipid peroxidation and antioxidant contents of kidney of Albino mice co-administrated with sildenafil citrate and alcohol
Authors: Soumya K. , Udayakumar Raju , Viswanathan K.
Published: April 2012

Male Wistar Albino mice were co-administrated with appropriate dose of sildenafil citrate and alcohol. The kidney samples of those animals were analyzed for lipid peroxidation and antioxidant contents. Lipid peroxidation was measured based on TBARS. Antioxidant such as SOD, CAT, GPx and GSH were also determined. From the present investigation, an enhanced level of TBARS accompanied by a decreased concentration of enzymic as well as non-enzymic antioxidants in kidney was detected for 30 days animals treated concomitantly with sildenafil citrate and alcohol. Increased level of lipid peroxidation lead to accumulation of free radicals and increased oxidative threat in kidney tissues. Also, the decreased concentration of antioxidant enzymes in renal tissues indicates the failure of antioxidant defence system.
Characterization and discrimination of nasopharyngeal carcinoma and nasopharyngeal normal cell lines using confocal Raman microspectroscopy
Authors: Ye Yuhuang , Chen Yang , Li Yongzeng , Su Ying , Zou Changyan , Chen Yanping , Ou Lin , Chen Rong , Zeng Haishan
Published: April 2012

Raman microspectroscopy can provide molecular-level information about the biochemical composition and structure of cells and tissues with excellent spatial resolution. In this study, Raman spectroscopy of individual cells from nasopharyngeal carcinoma cell lines C666-1, CNE2 and nasopharyngeal normal cell line NP69 are investigated for their differences. The spectral intensity ratio at 1449 and 1657 cm−1with a decision line of I1449/I1657=1.10 can very easily separate the tumor and normal cell lines into two groups. Principal component analysis (PCA) and linear discriminant analysis (LDA) are also used to classify different cell lines and achieved a specificity and sensitivity of 100 and 90%, respectively. The results support the potential utility of Raman spectroscopy for nasopharyngeal diagnosis.
Modeling of cytochrome P450 (Cyt P450, CYP) channels
Authors: Jankowski Christopher K. , Chiasson Julien B. , Dako Étienne , Doucet Kathy , Surette Marc E. , André Francois , Delaforge Marcel
Published: April 2012

The precise location of a substrate in cytochrome P450 (CYP) governs the orientation of the oxidation position. Such information is generally obtained from biochemical data, but modeling approaches have also been used to explain these locations. We used X-ray data and modeling techniques to distinguish between the series of putative linear or curved channels which lead the substrate from the outer side of the protein to the inner, and then into the heme pocket; these techniques were also used to identify the largest such channels. Two new methods for precisely determining the 3-D structure of proteins using X-ray crystallography were proposed in order to identify these channels: first, the use of both straight and curved channels, and second, the sphere method. These data are compared with Poulos channels, and with Caver (or Mol on line) modeling methodologies. Our methods were developed from studies of the interaction between cytochrome P450CAM(CYP101) fromPseudomonas putida(as expressed inEscherichia coli) and the indolic base β-carboline. Apart from the identification of potential access channels leading to the heme-containing active site, a new explanation was advanced for the substrate's hydroxylation position. The sphere method seems to have potential to become a general and direct method for prediction of substrate access channels from reduced- or low-resolution crystallographic data.
Spectroscopic and physical–chemical characterization of ambazone–glutamate salt
Authors: Muresan-Pop Marieta , Kacsó Irina , Filip Xenia , Vanea Emilia , Borodi G. , Leopold N. , Bratu I. , Simon S.
Published: April 2012

Ambazone monohydrate C8H11N7S · H2O (AMB), a well-known antimicrobial compound, was used together with Glutamic Acid C5H9NO4(Glu) to obtain a new solid form using the solvent-drop grinding procedure. The screening of the new solid form was best achieved by the combined use of X-ray Powder Diffraction (XRPD) and several spectroscopic techniques (Fourier Transformed Infrared Spectroscopy (FTIR), X-ray Photoelectron Spectroscopy (XPS), Raman and13C-NMR spectroscopy) together with Differential Scanning Calorimetry (DSC), Differential thermal analysis and thermogravimetry (DTA–TGA). The combination of the mentioned analytical techniques allows the compound to be assigned to an ambazone–glutamate salt which crystallizes in monoclinic system having the following lattice parameters:a=9.8352,b=4.7014,c=40.0987 Å and β=94.505°. DSC, TGA data and the before mentioned spectroscopic techniques support the ambazone–glutamate salt formation.
Spectroscopic studies on lipoprotein structure modification under oxidative stress
Authors: Tache Andreia , Litescu Simona-Carmen , Radu Gabriel-Lucian
Published: April 2012

Matrix assisted laser desorption–ionization time of flight (MALDI-ToF) and infrared techniques were used to study oxidative modification of low density lipoproteins (LDL), considered to have the key role in biological process that initiates and accelerates the development of cardiovascular disease. The early identification of lipoperoxidation products creates the opportunity of the efficient prevention of eventual oxidative damages. MALDI analysis of LDL subjected toin vitrooxidation process initiated by 2,2-azobis(2-amidinopropane) dihydrochloride revealed that some fragments of lipoprotein changed the molecular weight by 16 and 32 Da due to the oxygen or hydroxyl groups attachment, and peroxide or hydroperoxide formation, while Fourier Transformed Infrared studies proved that lipoprotein changes its protein secondary conformation from predominantlyα-helix in predominantlyβ-turn. The increase in free radicals concentration correlated to structural changes, and the presence of transitional metal ion, copper (II), in the oxidation process lead to an enhancing of the damaging effects of free radicals on lipoprotein substrate. It was shown that the toxic effects of oxidants are delayed by the presence of glutathione (10 mM), an endogenous antioxidant.
Thermodynamic and spectroscopic study on the binding of interaction anionic phthalocyanine with calf thymus DNA
Authors: Dezhampanah Hamid , Darvishzad Termeh , Aghazadeh Mehrnaz
Published: April 2012

The interaction between anionic form of copper (II) N,N',N",N'"-tetrasulfonated phthalocyanine Cu (tspc) and to calf thymus deoxyribonucleic acid (ct-DNA) is investigated by measuring UV-vis absorption and fluorescence spectroscopy in phosphate buffer. The binding constant and stoichiometry were determined by analysis of optical absorption spectra of phthalocyanine at various ct-DNA concentrations using SQUAD software. The static mode of fluorescence quenching of phthalocyanine by calf thymus deoxyribonucleic acid indicates the formation of a ground-state complex. The formation of ground-state complex is a spontaneous molecular interaction procedure in which outside groove binding through the formation of an axial bond between the base pairs of nucleotide and Cu in the central core of phthalocyanine.
A novel method for the detection of liver damage using fluorescence of hepatic mitochondria in a rat model following ischaemia/reperfusion injury of the small intestine
Authors: Tomečková Vladimíra , Štefanišinová Miroslava , Bilecová-Rabajdová Miroslava , Kriššáková Eliška , Tomečko Marián , Tóth Štefan , Pekárová Tímea , Mareková Mária
Published: April 2012

We present a novel method of assessing damage to the liver using fluorescence analysis of hepatic mitochondria following ischaemia/reperfusion of the small intestine in a rat model. This work is of substantial importance in understanding the syndrome of multiorgan failure after ischemia/transplantation of the small intestine. Mitochondria were isolated from six sample groups that had undergone three different experimental treatments: a control group; a treatment with ischaemia followed by reperfusion of the small intestine (IRx); and, a one hour ischaemia followed by reperfusion after transplant of the small intestine (TRx). The IR treatment was further subdivided into three groups: 1, 24 h and 30 days reperfusion – IR1, IR24, IR720, respectively. Concomitantly, the TR treatment was further subdivided: one group underwent a 1 h reperfusion and another group a 6 h reperfusion following ischaemia and transplant – groups TR1and TR6, respectively. Once treatment had been undergone, mitochondria were isolated and all five experimental groups – IR1, IR24, IR720, Tr1, Tr6– and their emission matrices were analysed compared with that of the control group (C). Comparing fluorescence values in zone A of all experimental groups with those of the control group indicated a reduction in aromatic amino acids in the mitochondria of all experimental groups. Comparison of fluorescent zone B of experimental groups with the control group identified a lack of oxygen in samples IR1, IR24, which was indicated though an increase in the fluorescence of the reduced pyridine nucleotide NADH+H+.
New solid form of Norfloxacin: Structural studies
Authors: Bratu I. , Borodi G. , KacsÓ Iren , Moldovan Z. , Filip C. , Dragan Felicia , Vasilescu M. , Simon S.
Published: April 2012

The aim of the present paper was to obtain new solid forms of Norfloxacin. For this purpose Norfloxacin was recrystallized from: acetic acid and its mixtures with several organic solvents. By recrystallization of Norfloxacin from acetic acid and from its mixture with several organic solvents a new solvate was found. To evidence this new solid form of Norfloxacin different investigation techniques were used: powder X-ray diffraction, FTIR, DSC,13C NMR spectroscopy and mass spectrometry. The solvate is consisting on Norfloxacin and acetic acid in 1:1 molar ratio and crystallizes in triclinic system and the cell parameters were determined also.
Application of FTIR spectroscopy coupled with chemometrics for authentication ofNigella sativaseed oil
Authors: Nurrulhidayah A. F. , Man Y. B. Che , Al-Kahtani H. A. , Rohman A.
Published: April 2012

The present study is intended to analyze the presence of grape seed oil (GSO) inNigella sativaL. seed oil (NSO) using Fourier transform infrared (FTIR) spectroscopy and gas chromatography (GC). FTIR spectroscopy coupled with multivariate calibration of partial least square can quantify the levels of GSO in NSO at wavelength number of 1114–1074, 1734–1382 and 3005–3030 cm–1. The coefficient of correlation (R2) obtained for the relationship between actual (x-axis) and FTIR predicted (y-axis) values are 0.981. The errors in cross validation and in prediction are 2.34% (v/v) and 2.37% (v/v), respectively.
Determination of extra virgin olive oil in quaternary mixture using FTIR spectroscopy and multivariate calibration
Authors: Rohman Abdul , Man Y. B. Che
Published: April 2012

The purpose of this study was to optimize Fourier transform infrared (FTIR) spectroscopy in combination with multivariate calibrations (partial least square and principle component regression) for determination of extra virgin olive oil (EVOO) in quaternary mixture systems with grape seed oil (GSO), rice bran oil (RBO) and walnut oil (WO). FTIR spectra of EVOO in quaternary mixtures were subjected to several treatments including mean centering (MC), standard normal variate, and spectra derivatives. The combined frequency regions of 1200–900 and 2949–2885 cm–1were used for determination of EVOO. Using partial least square calibration, FTIR normal spectra treated with MC model give the highest values of coefficient of determination (R2) and the lowest values of root mean square error of calibration (RMSEC). TheR2value obtained for the relationship between actual and FTIR predicted value of EVOO was >0.99 with RMSEC value of 1.55% (v/v). The developed PLS model was further used to calculate EVOO in prediction samples, and the root mean square error of prediction obtained was 3.65% (v/v).
Molecular relaxation processes in genomic DNA from leaf tissues: A surface-enhanced Raman spectroscopic study
Authors: Muntean Cristina M. , Bratu Ioan , Leopold Nicolae
Published: April 2012

In this work the SERS total half bandwidths of six genomic DNAs from ex vitro-grown apple leaf tissues (Malus domesticaBorkh., Fam. Rosaceae, cvs. Rebra, Goldrush, Florina, Romus 4, and the rootstocks M26, M9) and of five genomic DNAs fromin vitrogrown plants ofArnica montana(L.), Fam. Compositae,Astragalus peterfii(Jáv.), Fam. Fabaceae, strawberry (Duch.), Fam. Rosaceae, carnation (Dianthus caryophyllusL.), Fam. Caryophyllaceae, andKalanchoe x hybrida, Fam. Crassulaceae, respectively, have been measured. We have shown that surface-enhanced Raman scattering can be used to study the fast subpicosecond dynamics of DNA in the proximity of a metallic surface. The dependencies of the total half bandwidths and of the global relaxation times, on DNA molecular subgroup structure and on the type of genomic DNA, are reported.It is shown that changes in the subpicosecond surface dynamics of molecular subgroups in genomic DNAs from leaf tissues can be monitored with surface-enhanced Raman spectroscopy. In our study, the full widths at half-maximum (FWHMs) for the SERS bands of genomic DNAs from different leaf tissues, are typically in the wavenumber range from 15 to 30 cm–1for data set 1 and from 13 to 42 cm–1for data set 2. Besides, it can be observed that molecular relaxation processes studied in this work, have a global relaxation time smaller than 0.71 ps and larger than 0.35 ps (data set 1) and also varying between 0.25–0.82 ps for data set 2. A comparison between different ranges of FT-Raman and SERS band parameters, respectively, of DNA extracted from leaf tissues is given. We have found that the bands of DNA from Florina cultivar and Kalanchoe leaves, respectively, are suitable for the study of dynamical behaviour of molecular subgroups in nucleic acids extracted from different leaf tissues.
Spectrophotometric determination ofβ-blocker drugs by oxidation with bromate–bromide mixture and its analytical application to pharmaceutical preparations
Authors: El-Didamony Akram M. , Erfan Eman A. H.
Published: April 2012

Three visible spectrophotometric methods (A–C) were developed for the analysis of someβ-blocker drugs, namely atenolol (ATE) and timolol (TIM) based on their reactivity with bromine, generated in situ by the action of hydrochloric acid on bromate–bromide mixture. The determination of residual bromine is based on its ability to bleach the indigo carmine dye and measuring the absorbance at 610 nm (method A). Methods B and C involve treating the unreacted bromine with a measured excess of iron (II), the remaining iron (II) is complexed with 1,10-phenanthroline (method B) or with 2,2'-bipyridyl (method C) and measuring the increase in absorbance at 510 and 522 nm, respectively. In all the methods, the amount of bromine reacted corresponding to the drug content. Regression analysis of Beer's plot showed good correlation in the concentration ranges of 0.4–16.4, 0.8–10.4 and 0.4–12.8 µg/ml using methods A–C, respectively, for ATE and 14–38, 12–32 and 14–38 µg/ml using methods A–C, respectively, for TIM. The optimum reaction conditions and other analytical parameters are evaluated. No interference was observed from the additives and the applicability of the methods was tested by analyzing the pharmaceutical preparations containing the investigated drugs. Statistical comparison of the results with those of official methods shows excellent agreement and indicates no significant difference in precision.
Improved stability of blood glucose measurement in humans using near infrared spectroscopy
Authors: So C. F. , Chung Joanne W. Y. , Siu Maggie S. M. , Wong Thomas K. S.
Published: April 2012

Near infrared (NIR) spectroscopy has become a promising technique for blood glucose monitoring. However, an appropriate model of spectral response in humans is yet to be determined because of the reliability problem. In this study, 48 subjects were recruited. The subjects' left forearms were scanned using near infrared spectroscopy to obtain NIR spectra. Simultaneously, a blood sample of glucose was drawn. A new method based on Monte Carlo approach is applied for partial least squares (PLS), named as PLSMC, is proposed. A large numbers of models are built from calibration subsets which are randomly selected from the whole calibration set in order to minimize the noises. It is then determining the mean value over the models with high correlation and small prediction errors. The results show that the method can enhance the stability of PLS model. Also, the performance of the PLSMCshows more accurate prediction results as compared with conventional PLS.
Thermodynamic characterization of phthalocyanine–human serum albumin interaction
Authors: Dezhampanah Hamid , Bordbar Abdol Khalegh , Farshad Shamim
Published: April 2012

The thermodynamic of the binding of nickel (II) tetrasulfonated phthalocyanine anion [Ni(tspc)4–], to human serum albumin (HSA) was investigated in 5 mM aqueous phosphate buffer of pH 7.40 at 25°C using optical absorption spectroscopy. The results show that [Ni(tspc)4–] does not have any affinity for aggregation due to increasing of salt concentration and exists as monomers even in homogeneous aqueous solutions of high ionic strengths (more than 2 M NaCl). The binding constant (K) was obtained by analysis of optical absorption spectra of mentioned complex at various HSA concentrations using SQUAD software. The value ofKwas estimated to be 4.89×105±0.03 (M–1) at 25°C. The thermodynamic parameters were calculated by van’t Hoff equation. The enthalpy and entropy changes were 28.08 kJ/mol and 203.09 J/(mol?·?K) at 25°C, respectively. The results indicate that the binding is mainly entropy driven and the enthalpy is unfavorable for it, the hydrophobic forces thus playing a major role in the binding process.
Structural characterization of a variety of spider silks from Turkey using different biophysical techniques
Authors: İde Semra , Bayarı Sevgi Haman , Türkeş Tuncay , Mergen Y. Orhan , Çelik Ömer , Bütün Vural , Sargon Mustafa F. , Kocatepe Neslihan , Kriechbaum Manfred
Published: April 2012

Various experimental methods (XRD, FTIR, SAXS, DLS and SEM) were used to investigate structures of the silk samples weaved by spiders in Turkey. Silk samples were collected from the natural habitats belonging to the spider species (i.e., Near Salt Lake/şereflikoçhisar, İvriz Dam/Ereǧli-Konya, Karataş Lake/Burdur and several locations in Black Sea Region of Turkey). Among all collected species, Araneidae(Araneus angulatus, Argiope bruennichi, Argiope lobata, Larinoides cornutus), Eresidae(Eresus cinnaberinus), Agelenidae(Agelena labyrinthica), Oecobidae(Uroctea durandi), Miturgidae(Cheiracanthium erraticum), Salticidae(Heliophanus flavipes, Philaeus chrysops), Theridiidae(Steatoda paykulliana)and Gnaphosidae were found significant amongst other spider species. Structural differences and similarities of these species were reported. Diameter range of draglines, inter crystallite distance of nano-size structures, mean size range of nano-structure aggregations, crystallite size range, information about protein content were obtained. The mechanical properties of some silk fibers were also investigated.
Complexations of 2-thiouracil and 2,4-dithiouracil with Cd(SeCN)2and Hg(SeCN)2: NMR and anti-bacterial activity studies
Authors: Shaikh M. Nasiruzzaman , Al-Maythalony Bassem A. , Wazeer Mohammed I. M. , Isab Anvarhusein A.
Published: April 2012

Cadmium and mercury selenocyanate complexes of 2-thiouracil (TU) and 2,4-dithiouracil (DTU) ligands have been synthesized to form complexes of the type [M(SeCN)2(TU)] and [M(SeCN)2(DTU)] (where M is Cd2+or Hg2+) and studied by various spectroscopic techniques such as IR,1H and13C NMR in solution and in the solid state for13C,15N, and113Cd nuclei. Based on IR, and solution and solid-state13C NMR data, stronger cadmium bonding to the thiouracil was observed compared to that of mercury. Anti-bacterial activities of these complexes have been investigated with standard type culture ofEscherichia coli(MTCC 443),Klebsiella pneumoniae(MTCC 109),Pseudomonas aeruginosa(MTCC 1688),Salmonella typhi(MTCC 733) andStaphylococcus aureus(MTCC 737) and show that ligands exhibit more anti-bacterial activities than that of the corresponding Cd(II) and Hg(II) complexes.
Property study of a new silica nanoparticle delivery system of hydrophobic phthalocyanine using spectroscopic method
Authors: Lin Rui , Zhou Lin , Lin Yun , Wang Ao , Zhou Jia Hong , Wei Shao Hua
Published: April 2012

Tetra-tert-butyl zinc(II) phthalocyanine has attracted great attention as an effective photosensitizer in the field of photodynamic therapy. However, tetra-tert-butyl zinc(II) phthalocyanine is hydrophobic and trends to aggregate to form the inactive congeries in aqueous solution, which dramatically reduce its photodynamic activity. To solve this problem, tetra-tert-butyl zinc(II) phthalocyanine was encapsulated into silica nanoparticles using microemulsion method and its properties were studied using spectroscopic methods. After embedded inside the silica nanoparticles, the water-solubility, stability and monomer percent of phthalocyanine in water were greatly improved comparing with the free phthalocyanines, and therefore, its photo-induced singlet oxygen generation efficacy of drug-doped silica nanoparticles was improved. The results indicated that encapsulation hydrophobic phthalocyanine into silica nanoparticles was an effective way to solve their problems and promote their clinical application.
Ultrasensitive detection of genomic DNA from apple leaf tissues, using surface-enhanced Raman scattering
Authors: Muntean Cristina M. , Leopold Nicolae , Halmagyi Adela , Valimareanu Sergiu
Published: April 2012

Ultrasensitive detection of nucleic acids is demonstrated through exploiting the effect of surface-enhanced Raman scattering (SERS). In this work the SERS spectra of eight genomic DNAs from leaves of apple trees grown in the field (Malus domesticaBorkh., Fam.Rosaceae, cultivars. Florina, Idared, Rebra, Goldrush, Romus 3, Romus 4 and the rootstocks M9 and M26) have been analyzed in the wavenumber range 200–1800 cm–1. SERS signatures, spectroscopic band assignments and structural interpretations of these plant genomic DNAs are reported. SERS spectra of nucleic acids are compared here with caution, because these signals are time-dependent and are strongly influenced by DNA amount in the measured sample volume. Similarities of the SERS spectra of genomic DNAs extracted from apple leaves of Goldrush, Rebra and Florina cultivars, respectively, have been detected. Besides, the SERS spectra, corresponding to DNA from M9, Romus 4 and M26, leaves, respectively, show similar features and well resolved bands. Based on this work, specific plant DNA-ligand interactions or DNA structural changes induced by plant stress conditions associated with their natural environment, might be further investigated using surface-enhanced Raman spectroscopy.
Laser-induced chlorophyll fluorescence and reflectance spectroscopy of cadmium treatedTriticum aestivumL. plants
Authors: Pandey Jitendra Kumar , Gopal R.
Published: April 2012

The present study deals with laser-induced chlorophyll fluorescence (LICF) spectra, reflectance spectra and fluorescence induction kinetics (FIK) curves ofTriticum aestivumL. plants treated with different concentrations of cadmium (0.01, 0.1 and 1.0 mM). LICF spectra were recorded in the region of 650–780 nm using violet diode laser (405 nm) and FIK curves were recorded at 685 and 730 nm using red diode laser (635 nm) for excitation. Reflectance spectra were recorded in the region of 400–800 nm using spectrophotometer with an integrating sphere. The fluorescence intensity ratios (FIR) were determined from LICF spectra, vitality index (Rfd) from FIK curves and narrow band vegetation index (NBVI) from reflectance spectra. These parameters along with plant growth parameters and photosynthetic pigment contents were used to analyze the effect of cadmium on wheat plants. The results clearly show that lower concentration of Cd (0.01 mM) shows stimulatory response; whereas higher concentrations (0.1 and 1.0 Mm) are hazardous for plant growth, photosynthetic pigments and photosynthetic activity of wheat plants.
Spectroscopic impact on protein and carbohydrate inherent molecular structures of barley, oat and corn combined with wheat DDGS
Authors: Abeysekara S. , Damiran D. , Yu P.
Published: April 2012

The objectives of this experiment were to use non-invasive and non-destructive infrared molecular spectroscopy as a novel approach to explore and identify protein and carbohydrate molecular structure spectral features of DDGS (dried distillers grain solubles from wheat,Triticum aestivum) and its combinations with barley (Hordeum vulgare), corn (Zea mays) and oat (Avena sativa). The spectral parameters assessed in this study included amides, protein molecular structures ofα-helix andβ-sheet, lignin, cellulosic compounds (CeC) and nonstructural carbohydrates (NSC). The results of the study show that the combinations of DDGS with cereal grains significantly changed (P< 0.05) protein and carbohydrate structures and protein secondary structure. The use of FT/IR molecular spectroscopy in terms of identification of inherent structural changes was remarkable. The combination of DGGS with different grains alters the constituents and intrinsic molecular structures. This change would improve the nutritional quality and digestive characteristics of the feed. Further studies are recommended to evaluate the effect on digestibility, availability and its structural correlation.
Raman spectral statistical classification of nasopharyngeal carcinoma and nasopharyngeal normal cell lines based on support vector classification
Authors: Chen Yang , Sun Lei , Huang Yangwen , Ou Lin , Su Ying
Published: April 2012

Raman spectroscopy (RS) has been used in the discrimination of normal and tumor cells for years. It is very important to validate an existing classification model using different algorithms. In this work, two algorithms of support vector classification (SVC) are utilized to validate our previous work about a LDA classification model of nasopharyngeal carcinoma (NPC) cell lines C666-1, CNE2 and nasopharyngeal normal cell line NP69. All of these two SVC algorithms use the same data set as the previous LDA model and, achieve great sensitivity and specificity. The final results show that our previous LDA classification model could be supported by different SVC algorithms and this demonstrates our classification model is reliable and may be helpful to the realization of RS to be one of diagnostic techniques of NPC.
Interaction betweenPlectranthus barbatusherbal tea components and human serum albumin and lysozyme: Binding and activity studies
Authors: Falé Pedro L. V. , Ascensão Lia , Serralheiro Maria L. M. , Haris Parvez I.
Published: April 2012

Anti-cholinesterase and antioxidant active constituents ofPlectranthus barbatusaqueous extract were found in plasma of rats after its administration – rosmarinic acid, luteolin and apigenin. The aim of the present work is to determine if the extract components can interact with human plasma proteins, namely albumin and lysozyme. Protein intrinsic fluorescence analysis showed that the plant phenolic compounds may bind to albumin, the main transport protein in plasma, and to lysozyme. The estimated thermodynamic parameters suggest that the main intermolecular interaction is hydrophobic association. FTIR analysis of the protein amide bands showed that the plant extract components do not alter the secondary structure of either albumin or lysozyme, however the rate of hydrogen–deuterium exchange suggests that tertiary structure changes might have occurred. An increase of hydrogen deuterium exchange suggests that rosmarinic acid may bind to the fatty acid binding sites in albumin, while luteolin and apigenin may bind to the drug binding sites. The plant extract components also inhibit lysozyme activity with IC50values around 100 μM. ThereforeP. barbatusherbal tea, rosmarinic acid, luteolin and apigenin interact and may be transported by albumin and lysozyme. The inhibition of lysozyme activity may be an additional mechanism for its anti-inflammatory activity.
Comparison of partial least squares and artificial neural network chemometric techniques in determination of sulfamethoxazole and trimethoprim in pharmaceutical suspension by ATR–FTIR spectrometry
Authors: Khanmohammadi M. , Dallali N. , Bagheri Garmarudi A. , Zarnegar M. , Ghasemi K.
Published: April 2012

Partial Least Square (PLS) and Artificial Neural Network (ANN) techniques were compared during development of an analytical method for quantitative determination of sulfamethoxazole (SMX) and trimethoprim (TMP) in Co-Trimoxazole®suspension. The procedure was based on Attenuated Total Reflectance Fourier Transform Infrared (ATR–FTIR) spectrometry. The 800–2500 cm−1spectral region was selected for quantitative analysis.R2and relative error of prediction (REP) in PLS technique were (0.989, 2.128) and (0.986, 1.381) for SMX and TMP, respectively. These statistical parameters were improved using the ANN models considering the complexity of the sample and the speediness and simplicity of the method.R2and RMSEC in modified method were (0.997, 1.064) and (0.997, 0.634) for SMX and TMP, respectively.
Investigation on the interactions of lymphoma cells with paclitaxel by Raman spectroscopy
Authors: Lin Duo , Lin Juqiang , Wu Yanan , Feng Shangyuan , Li Yongzeng , Yu Yun , Xi Gangqin , Zeng Haishan , Chen Rong
Published: April 2012

The single-cell Raman spectra of human Burkitt's lymphoma cells (CA46) including cells treated with different doses of paclitaxel and controls without paclitaxel can be detected by confocal micro-Raman spectroscopy. It shows that the Raman bands at 1094 cm–1assigned to the symmetric stretching vibration mode of O–P–O in the DNA backbone, 1338 cm–1and 1578 cm–1due to adenine and guanine of DNA all decrease in intensity with increasing drug dose. On the contrary, the intensity of peaks at 1257 cm–1due to characteristic vibration ofa-helix of Amide III and 1658 cm–1due to characteristic vibration ofa-helix of Amide I both increases with increasing drug dose. Multivariate statistical methods, such as Principle Components Analysis (PCA) and Linear Discriminant Analysis (LDA) were employed to discriminate normal lymphoma cells (CA46) and cells treated with different doses of paclitaxel. It was found that the sensitivity and specificity of differentiating the treated and untreated cell groups increase with drug doses and approach 100% for the high drug dose, consistent with the perception that the cytotoxicity increases with drug dose. These results suggest that Raman spectroscopy combined with multivariate analysis could become a useful tool for assessing the cytotoxicity of drugs such as paclitaxel on human lymphoma cells.
Breast tissue characterization byin vivoMagnetic Resonance Spectroscopy (MRS)
Authors: Jagannathan N. R.
Published: April 2012

In vivomagnetic resonance spectroscopy (MRS) is a sensitive technique for metabolic evaluation of normal, benign and malignant tissues and is rapidly evolving as a clinical tool for diagnosis, characterization and monitoring the therapeutic response of tumor. The proton (1H) MR spectra of normal breast tissues are characterized by high fat content while tumor tissues have higher water content. From the respective peak areas, the water–fat (W–F) ratio can be calculated. Thein vivo1H MR spectrum obtained with water and fat suppression from malignant breast tissues are characterized by a peak at 3.2 ppm corresponding to choline-containing metabolites (tCho) and has been shown as a reliable biochemical marker of malignancy. With developments in MR methodology, it is possible to determine thein vivoabsolute quantification of tCho that provide an opportunity to have cut-off values for the discrimination of normal, benign and malignant breast tissues. Both W–F ratio and the concentration of tCho have been demonstrated to be useful in monitoring the effect of therapy in breast cancer patients. In patients receiving chemotherapy, reduction of W–F ratio and the concentration of tCho were observed in association with the reduction of the primary tumor size indicating its use as non-invasive indicators of favorable clinical outcome of therapy. Studies showed that addition of MRS investigation increases the specificity of MRI. This article reviews some salient features ofin vivoMRS and its role in the diagnosis and treatment management of breast cancer patients.
Monitoring of adipogenic differentiation at the single-cell level using atomic force microscopic analysis
Authors: Kwon Young-Nam , Kim Won Kon , Lee Sang-Hak , Kim Keewon , Kim Eun Young , Ha Tai Hwan , Han HyoukSoo , Bae Kwang-Hee
Published: April 2012

Adipogenesis plays an important role in energy homeostasis by storing excess energy as lipid droplets. However, these reservoirs are implicated in a host of major human health problems, such as obesity. Elucidation of the mechanisms underlying adipogenesis is thus crucial to overcome these problems. The preadipocyte cell lines represent an optimal model to examine adipogenesis. Cells differentiate into adipocytes with various speeds of conversion and fat accumulation. Here, we have presented a novel method for detecting adipogenic differentiation at the single-cell level using atomic force microscopic analysis. Data obtained with this method revealed a good correlation between membrane stiffness and the degree of adipogenic differentiation. Although we could not determine the underlying cause for membrane stiffness reduction during adipogenic differentiation, the technique clearly offers advantages over the existing detection systems, such as lipid drop staining and extraction. Furthermore, the degree of adipogenic differentiation at the single-cell level can be detected with this method.
Algorithm construction methodology for diagnostic classification of near-infrared spectroscopy data
Authors: Guevara Ramón , Stothers Lynn , Macnab Andrew
Published: April 2012

Background: Near-infrared spectroscopy (NIRS) has recognized potential but limited application for non-invasive diagnostic evaluation. Data analysis methodology that reproducibly distinguishes between the presence or absence of physiologic abnormality could broaden clinical application of this optical technique.Methods: Sample data sets from simultaneous NIRS bladder monitoring and invasive urodynamic pressure-flow studies (UDS) are used to illustrate how a diagnostic algorithm is constructed using classification and regression tree (CART) analysis. Misclassification errors of CART and linear discriminant analysis (LDA) are computed and examples of other urological NIRS data likely amenable to CART analysis presented.Results: CART generated a clinically relevant classification algorithm (error 4%) using 46 data sets of changes in chromophore concentration composed of the whole time series without specifying features. LDA did not (error 16%). Using CART NIRS data provided comparable discriminant ability to the UDS diagnostic nomogram for the presence or absence of obstructive pathology (88% specificity, 84% precision). Pilot data examples from children with and without voiding dysfunction and women with mild or severe pelvic floor muscle dysfunction also show potentially diagnostic differences in chromophore concentration.Conclusions: CART analysis can likely be applied in other NIRS monitoring applications intended to classify patients into those with and without pathology.
Structural characterization of recombinant bovine Goαby spectroscopy and homology modeling
Authors: Tiber Pinar Mega , Orun Oya , Nacar Cevdet , Sezerman Ugur Osman , Severcan Feride , Severcan Mete , Matagne André , Kan Beki
Published: April 2012

Go, a member of heterotrimeric guanine nucleotide-binding proteins, is the most abundant form of G protein in the central and peripheral nervous systems. Goαhas a significant role in neuronal development and function but its signal transduction mechanism remains to be clarified. In this study, the bovine Goαsubunit was overexpressed and purified into homogeneity. Its activity was studied using [35S] GTPγS binding, intrinsic fluorescence and BODIPY assays. The secondary structure was determined by both FTIR and CD spectroscopy as 42.3%α-helix, 13.4%β-sheet and 24.3%β-turn. A theoretical structure model was constructed. The structure from homology modeling is in very good agreement with the crystal structure of mouse Goαsubunit except for the loop betweenαB–αC helices. This model was docked to the mouse RGS16 molecule. T117 on theαB–αC loop of Goαinteracted with K172 on RGS16 as opposed to the T117 and K164 interaction in mouse.