This document summarizes research on the adsorption behavior of hyaluronidase enzyme onto silver nanoparticles and polymethyl methacrylate (PMMA) bone substitute surfaces. Surface-enhanced Raman scattering (SERS) and infrared (IR) spectroscopy techniques were used to analyze the adsorption. SERS spectra of hyaluronidase adsorbed to silver nanoparticles showed well-resolved Raman signals and indicated oxygen adsorption from functional groups. IR analysis of PMMA incubated with hyaluronidase showed shifts in amide band positions, suggesting changes to secondary structure upon adsorption. Band deconvolution and fitting of amide peaks revealed decreases in α-helix and β-sheet content for adsorbed hyaluronidase, with increases
SIMONA CAVALU_Adsorption behavior of hyaluronidase onto silverSimona Cavalu
Surface enhanced Raman scattering (SERS) and ATR-FTIR spectroscopy was applied in this work, in order to get
information about the adsorption behavior of the title macromolecule with respect to different surfaces. In this case, the
silver substrate can be considered as artificial substrate and the investigations regarding the mechanisms of adsorption can
be useful in order to elucidate the active site properties of this enzyme. Our purpose is to study the adsorption mechanism
of hyaluronidase onto silver nanoparticles and PMMA (polymethyl methacrylate) substrates as well as qualitative and
quantitative aspects regarding perturbations of protein secondary structure (α-helix, β-sheet and unordered structures) upon
adsorption, using deconvolution techniques.
IRJET- Effect of Intensity - Temperature on Ultrasonic Dextran DegradationIRJET Journal
This document discusses an experiment investigating the effect of ultrasound intensity and temperature on the degradation of dextran solutions. Dextran, a polysaccharide produced by bacteria, was sonicated at various intensities (19.2-34.6 W/cm2) and temperatures (10-25°C) for up to 150 minutes. The specific viscosity of the dextran solutions was measured over time using a capillary viscometer to analyze degradation kinetics. Theoretical models were used to determine degradation constants and limit viscosities. The results showed that degradation constants and limit viscosities decreased with increasing intensity and temperature, as higher intensities and temperatures enhanced degradation through cavitation and vapor pressure effects.
This document summarizes a new microscopy technique called STORM (stochastic optical reconstruction microscopy) that achieves super-resolution below the diffraction limit of light. STORM works by switching individual fluorophores between fluorescent and dark states and localizing their positions with nanometer precision over many imaging cycles. This allows reconstruction of an overall image with 20 nm resolution. The document demonstrates STORM imaging of DNA structures labeled with photo-switchable dyes, resolving features spaced 40 nm apart. STORM is presented as a general technique for high-resolution biological imaging below the diffraction limit.
This document discusses spectrophotometry techniques for measuring light absorption by molecules. It covers the electromagnetic spectrum, Beer-Lambert law, applications of UV-vis spectroscopy like determining cell density and protein concentration, and methods for measuring absorbance of molecules like DNA, RNA, proteins, and other biological compounds. Key concepts explained include the relationship between absorbance, molar extinction coefficient, concentration, and path length in the Beer-Lambert law.
Piperazine derivatives as iron chelators a potentialSteve Huvelle
This document summarizes a study that synthesized new piperazine derivatives designed as iron chelators and assessed their potential to prevent iron-induced neurotoxicity. The compounds were able to provide sustained neuroprotection to dopaminergic neurons vulnerable in Parkinson's disease. Spectrophotometric titration showed the compounds have high affinity for iron and can chelate iron, while an in vitro cellular model demonstrated their neuroprotective effects. The document then details the experimental methods used for synthesizing the piperazine derivatives and assessing their iron-chelating properties and neuroprotective abilities.
The document discusses the health effects of traffic-related air pollution. It finds that exposure to airborne particulate matter (PM) from traffic is associated with increased mortality and hospital admissions for respiratory and cardiovascular diseases. Ultrafine particles from traffic emissions promote early atherosclerosis and systemic oxidative stress. Studies show increased risks of childhood asthma and cardiovascular diseases for those living near busy roads. Further research is needed to identify the most toxic pollutant sources and biological mechanisms of health impacts.
A study the effect of zr o3 on the electrical and mechanical propertiesAlexander Decker
This document summarizes a study on the effect of adding ZrO3 on the electrical and mechanical properties of PMMA-Cr2O3 polymer composites. The study found that adding ZrO3 increased the electrical conductivity and ultrasound velocity of the composites. It also increased the relaxation amplitude, relaxation time, and bulk modulus while decreasing the molar conductivity, disintegration degree, and compressibility. The changes in properties are due to interactions between the polymer matrix and ZrO3 filler on the molecular level that affect ion motion and polymer chain structure. The addition of ZrO3 thus improves both the electrical and mechanical properties of the PMMA-Cr2O3 composite for applications.
Spectroscopic study on Thiourea and Thiosemicarbazide in Non-aqueous mediaIOSR Journals
The spectroscopic methods of the different regions of the Electromagnetic spectrum are the most powerful and useful techniques available for the understanding of molecular structure, nature of bonding between atoms, confirmation analysis, symmetry of molecules, ions in crystals and so forth. The high resolution IR spectroscopic studies have recently received a great thrust due to the advent of advanced Fourier transform spectrometers. In the present investigation the spectral changes are studied in the vibrational spectra of thiourea, thiosemi carbazide in non aqueous solvent. The H2N stretching vibrations observed at 3371cm¯¹, 3259cm¯¹, & 3156cm¯¹ indicated that 3 different types of NH2 groups arising out of tautomeric form. The results obtained from the present study confirm that the solute – solvent interactions occurring in the solution is through intermolecular H- bonding.
SIMONA CAVALU_Adsorption behavior of hyaluronidase onto silverSimona Cavalu
Surface enhanced Raman scattering (SERS) and ATR-FTIR spectroscopy was applied in this work, in order to get
information about the adsorption behavior of the title macromolecule with respect to different surfaces. In this case, the
silver substrate can be considered as artificial substrate and the investigations regarding the mechanisms of adsorption can
be useful in order to elucidate the active site properties of this enzyme. Our purpose is to study the adsorption mechanism
of hyaluronidase onto silver nanoparticles and PMMA (polymethyl methacrylate) substrates as well as qualitative and
quantitative aspects regarding perturbations of protein secondary structure (α-helix, β-sheet and unordered structures) upon
adsorption, using deconvolution techniques.
IRJET- Effect of Intensity - Temperature on Ultrasonic Dextran DegradationIRJET Journal
This document discusses an experiment investigating the effect of ultrasound intensity and temperature on the degradation of dextran solutions. Dextran, a polysaccharide produced by bacteria, was sonicated at various intensities (19.2-34.6 W/cm2) and temperatures (10-25°C) for up to 150 minutes. The specific viscosity of the dextran solutions was measured over time using a capillary viscometer to analyze degradation kinetics. Theoretical models were used to determine degradation constants and limit viscosities. The results showed that degradation constants and limit viscosities decreased with increasing intensity and temperature, as higher intensities and temperatures enhanced degradation through cavitation and vapor pressure effects.
This document summarizes a new microscopy technique called STORM (stochastic optical reconstruction microscopy) that achieves super-resolution below the diffraction limit of light. STORM works by switching individual fluorophores between fluorescent and dark states and localizing their positions with nanometer precision over many imaging cycles. This allows reconstruction of an overall image with 20 nm resolution. The document demonstrates STORM imaging of DNA structures labeled with photo-switchable dyes, resolving features spaced 40 nm apart. STORM is presented as a general technique for high-resolution biological imaging below the diffraction limit.
This document discusses spectrophotometry techniques for measuring light absorption by molecules. It covers the electromagnetic spectrum, Beer-Lambert law, applications of UV-vis spectroscopy like determining cell density and protein concentration, and methods for measuring absorbance of molecules like DNA, RNA, proteins, and other biological compounds. Key concepts explained include the relationship between absorbance, molar extinction coefficient, concentration, and path length in the Beer-Lambert law.
Piperazine derivatives as iron chelators a potentialSteve Huvelle
This document summarizes a study that synthesized new piperazine derivatives designed as iron chelators and assessed their potential to prevent iron-induced neurotoxicity. The compounds were able to provide sustained neuroprotection to dopaminergic neurons vulnerable in Parkinson's disease. Spectrophotometric titration showed the compounds have high affinity for iron and can chelate iron, while an in vitro cellular model demonstrated their neuroprotective effects. The document then details the experimental methods used for synthesizing the piperazine derivatives and assessing their iron-chelating properties and neuroprotective abilities.
The document discusses the health effects of traffic-related air pollution. It finds that exposure to airborne particulate matter (PM) from traffic is associated with increased mortality and hospital admissions for respiratory and cardiovascular diseases. Ultrafine particles from traffic emissions promote early atherosclerosis and systemic oxidative stress. Studies show increased risks of childhood asthma and cardiovascular diseases for those living near busy roads. Further research is needed to identify the most toxic pollutant sources and biological mechanisms of health impacts.
A study the effect of zr o3 on the electrical and mechanical propertiesAlexander Decker
This document summarizes a study on the effect of adding ZrO3 on the electrical and mechanical properties of PMMA-Cr2O3 polymer composites. The study found that adding ZrO3 increased the electrical conductivity and ultrasound velocity of the composites. It also increased the relaxation amplitude, relaxation time, and bulk modulus while decreasing the molar conductivity, disintegration degree, and compressibility. The changes in properties are due to interactions between the polymer matrix and ZrO3 filler on the molecular level that affect ion motion and polymer chain structure. The addition of ZrO3 thus improves both the electrical and mechanical properties of the PMMA-Cr2O3 composite for applications.
Spectroscopic study on Thiourea and Thiosemicarbazide in Non-aqueous mediaIOSR Journals
The spectroscopic methods of the different regions of the Electromagnetic spectrum are the most powerful and useful techniques available for the understanding of molecular structure, nature of bonding between atoms, confirmation analysis, symmetry of molecules, ions in crystals and so forth. The high resolution IR spectroscopic studies have recently received a great thrust due to the advent of advanced Fourier transform spectrometers. In the present investigation the spectral changes are studied in the vibrational spectra of thiourea, thiosemi carbazide in non aqueous solvent. The H2N stretching vibrations observed at 3371cm¯¹, 3259cm¯¹, & 3156cm¯¹ indicated that 3 different types of NH2 groups arising out of tautomeric form. The results obtained from the present study confirm that the solute – solvent interactions occurring in the solution is through intermolecular H- bonding.
Application of uv visible spectroscopy in pharmaceutical industryFarhad Ashraf
UV-visible spectroscopy can be used for clinical and pre-clinical applications in cancer diagnosis and analysis. It allows non-invasive measurement of biomarkers like tumor oxygenation, angiogenesis, redox state, and morphology. Spectroscopy measures how light interacts with tissue via absorption and fluorescence of chromophores and fluorophores. This optical signature contains physiologically meaningful information about cancer progression and treatment response that can provide insights not available from traditional pathology. Quantitative optical techniques have the potential to improve cancer management with personalized, molecularly-informed assessments.
Abstract
A small set of amphetamines has been analyzed by gas chromatography (GC) high-resolution time-of-flight mass spectrometry (TOFMS) using a microplasma photoionization (MPPI) soft-ionization source. This plasma-based, wavelength selectable ionization source enables ionization of the test compounds and their corresponding derivatives at ~8-12 eV that is a softer alternative to electron ionization at 70 eV. Three plasma gases were used in this study: Xe plasma that emits photons at resonance lines of 9.57 eV and 8.44 eV; Kr plasma at 10.63 eV and 10.02 eV, and Ar plasma at 11.82 eV and 11.61 eV. Derivatization of the test compounds with trifluoroacetic anhydride and α-methoxy-α-(trifluoromethyl)-phenylacetyl pyrazole was evaluated because the MPPI mass spectra of the underivatized amphetamines yield primarily iminium ions, which make the identification of the test compounds by GC-TOFMS inconclusive. The MPPI mass spectra of the TFA-derivatized amphetamines yield abundant molecular ions, when using Xe as plasma gas, and enough fragment ions with the Ar plasma that can help in formula generation. The structure elucidation of two "known unknowns" designer drugs using this "tunable" soft-ionization source and a high-resolution TOF mass spectrometer is presented in this study.
PRISM Spring 2012 drug DNA binding poster Bob Rawal
This study developed a fluorescence-based method to determine the preferential DNA binding modes of drug molecules. Two nucleic acid dyes (TP3 and DAPI) that bind DNA through different modes (intercalation and minor groove binding, respectively) were used in fluorescence quenching assays with 11 drug molecules. The results identified the likelihood of intercalation for each molecule, with netropsin, berenil, pyrocatechol violet, sunset yellow, tartrazine, and new coccine preferentially binding through the minor groove and congo red, janus green, and brilliant blue preferentially binding via intercalation. NMR studies of 3 molecules corroborated the fluorescence assay findings. The method provides
Effect of doping ratio on ftir spectrum of coumarin dopedAlexander Decker
This document discusses a study on the effect of doping ratio on the FTIR spectrum of coumarin doped polystyrene films. Coumarin and polystyrene samples were prepared with different doping ratios of coumarin solution. FTIR analysis showed changes in the spectra as the doping ratio increased. Peaks associated with the coumarin dye appeared as the doping ratio increased from 10 to 60 ml, indicating the coumarin was affecting the polymer structure. The study provides information on how doping ratio can influence the spectroscopic properties of dye doped polymer films as measured by FTIR.
This document discusses using ion mobility mass spectrometry to quantify linear impurities in cyclic polylactide samples. It finds that the method was unable to accurately determine low levels of linear contamination, as cyclic ions at lower polymerization degrees were less likely to adopt the triply charged state analyzed. This led to an overestimation of linear content. Considering additional charge states or shifting ion conformations may help address this issue in future work. The document introduces the topic, experimental methods, data analysis, results showing inconsistent quantification at different polymerization degrees, and conclusions about limitations and potential improvements.
The IOSR Journal of Pharmacy (IOSRPHR) is an open access online & offline peer reviewed international journal, which publishes innovative research papers, reviews, mini-reviews, short communications and notes dealing with Pharmaceutical Sciences( Pharmaceutical Technology, Pharmaceutics, Biopharmaceutics, Pharmacokinetics, Pharmaceutical/Medicinal Chemistry, Computational Chemistry and Molecular Drug Design, Pharmacognosy & Phytochemistry, Pharmacology, Pharmaceutical Analysis, Pharmacy Practice, Clinical and Hospital Pharmacy, Cell Biology, Genomics and Proteomics, Pharmacogenomics, Bioinformatics and Biotechnology of Pharmaceutical Interest........more details on Aim & Scope).
All manuscripts are subject to rapid peer review. Those of high quality (not previously published and not under consideration for publication in another journal) will be published without delay.
Core-cladding mode resonances of long period fiber grating in concentration s...IOSR Journals
Long period fiber grating (LPFG) is photoinduced fiber device that facilitates the coupling of core
mode to different cladding modes resulting into series of transmission dips in the transmission spectrum. Here
we present LPFG chemical sensor to determine the concentration of Manganese in water at ppm level. We
fabricated LPFG of period 600μm in single mode communication fiber using 12W carbon dioxide laser
applying point by point method. The fabricated LPFG is directly used as chemical sensor since cladding modes
coupled to core mode directly come in contact with surrounding chemicals. Concentration of manganese in our
collected sample is found to be 0.0329ppm. The result is verified with sophisticated Atomic Absorption
Spectrometer (AAS).
This document summarizes an experiment on ultrafiltration and gel electrophoresis. For ultrafiltration, the goals were to understand membrane separation principles and parameters like osmotic pressure and fouling. Experiments tested filtration rate with different protein concentrations. Results showed osmotic pressure had a greater effect on mass transfer than fouling. For gel electrophoresis, the goals were to separate and measure molecular weights of pepsin and rennet using SDS-PAGE. Results showed crude pepsin, pure pepsin, and rennet-pepsin mixture were close to literature values, while rennet alone had some unexpected bands possibly from breakdown.
This document discusses the use of positron annihilation spectroscopy to analyze the free volume nanohole distribution in polymers and its correlation to the physico-chemical properties of polymers. It provides background on positron annihilation spectroscopy and how it can be used to measure free volume in polymers. The document then describes several studies that use this technique to analyze the influence of free volume properties on the swelling of polymer hydrogels, structure-property relationships in modified epoxy resins, and free volume and interfacial interactions in epoxy clay composites.
Quantitative Analysis of 30 Drugs in Whole Blood by SPE and UHPLC-TOF-MSAnnex Publishers
The document describes the development and validation of an UHPLC-TOF-MS method for the quantitative analysis of 30 drugs in whole blood. Key points:
- The method was used to simultaneously screen for and quantify 30 common drugs and drugs of abuse in blood samples.
- Samples underwent solid phase extraction, were separated via UHPLC and analyzed by TOF-MS. Extraction recoveries ranged from 41-111% and matrix effects ranged from -13% to 50%.
- Calibration curves for each drug showed good linearity. Lower limits of quantification ranged from 0.005-0.05 mg/kg. Accuracy and precision were satisfactory above the LOQ.
- The validated method allows for simultaneous screening
This document discusses a study on the synthesis, molecular structure, and quantum chemical computational interpretations of (E)-N'-(3,4-Dimethoxybenzylidene)-nicotinohydrazide monohydrate. Density functional theory calculations were performed using B3LYP and M06-2X levels of theory to optimize the geometry and study vibrational modes, natural bond orbital analysis, HOMO-LUMO analysis, molecular electrostatic potential, and thermodynamic properties. FT-IR, FT-Raman, and UV-Vis spectroscopy experiments were also carried out. The results from quantum chemical calculations showed good agreement with experimental data and provided insights into the structural stability and charge transfer interactions
Synthesis, Spectroscopic (FT-IR, FT-Raman), First Order HYPERPOLARIZABILITY a...IRJET Journal
This document discusses the synthesis, spectroscopic analysis, and density functional theory calculations of the molecule (2E)-N-phenyl-3-(4H-pyran-4-yl)prop-2-enamide (P3P2E). Fourier transform infrared and Raman spectroscopy were used to analyze the vibrational modes of the molecule experimentally. Density functional theory with B3LYP/6-311++G(d,p) was used to calculate the molecular geometry, vibrational frequencies, and other properties. The theoretical calculations showed good agreement with the experimental spectroscopic data. Frontier molecular orbital analysis and other properties like first hyperpolarizability were also calculated to understand the reactivity and nonlinear optical behavior of the
Presentation on the basic Maldi-Imaging workflow with some information on how...Diane Hatziioanou
Presentation on the basic Maldi-Imaging workflow with some information on how it works. This presentation was prepared for a group meeting and is focused almost entirely on the process of MALDI-Imaging to give the group leaders an understanding of the process as well as some important information on how to make it work well.
This document summarizes a study that synthesized and characterized the organic compound 1-(pyrazin-2-yl) piperidin-2-ol (PPOL) using computational and experimental methods. Density functional theory calculations were performed to determine the optimized geometry, vibrational frequencies, and electronic properties of PPOL. Experimental Fourier transform infrared, Raman, nuclear magnetic resonance, and UV–visible spectroscopy data were also collected and compared to the computational results. The calculations provide information on the molecular structure, vibrational modes, thermodynamic properties, and electronic structure of PPOL.
This document provides an overview of mass spectrometry. It begins with definitions and explanations of key concepts like the principle of mass spectrometry and instrumentation. It then describes various components of mass spectrometers like ion sources and types of ionization. Two ionization methods - fast atom bombardment and matrix-assisted laser desorption/ionization - are explained in detail. The document also mentions several types of mass analyzers and applications of mass spectrometry. In under 3 sentences, the document provides an introduction to mass spectrometry, explains that it involves ionizing samples and separating the ions by mass to charge ratio, and describes some common uses and components of mass spectrometry systems.
This document reports on the synthesis, molecular structure, spectroscopic characterization, and quantum chemical calculation of (2E)-1-(5-chlorothiophen-2-yl)-3-(2,3,4-trimethoxyphenyl)prop-2-en-1-one. Single crystal X-ray diffraction, FT-IR, FT-Raman, and UV–vis spectra were recorded experimentally and compared to calculations. Density functional theory was used to optimize geometry, calculate vibrational frequencies, and predict structural and spectroscopic parameters. Natural bond orbital analysis was performed to analyze stability, hyperconjugation, and charge delocalization. Time-dependent density functional theory was used to calculate electronic transitions, absorption wavelengths, and frontier
MALDI-TOF is a soft ionization technique that allows analysis of biomolecules like proteins and DNA. It works by using a laser to trigger desorption of analyte molecules that have been coated with an absorbing matrix, ionizing the molecules for analysis by mass spectrometry. The matrix facilitates the ionization process and protects the fragile biomolecules. MALDI is commonly paired with time-of-flight mass spectrometry due to TOF-MS's ability to analyze a wide range of molecular masses produced through the MALDI ionization process.
Some Biophysical Methods for Demonstrating Comparability of Conformation and ...KBI Biopharma
Sedimentation velocity, circular dichroism spectroscopy, light scattering, and dynamic light scattering are effective methods for demonstrating the comparability of protein conformation and aggregation between product lots:
1) Sedimentation velocity precisely measures sedimentation coefficients, which are highly sensitive to small conformational differences, and can detect aggregates as low as 0.2%;
2) Circular dichroism spectroscopy provides spectral fingerprints of secondary and tertiary structure that are sensitive to conformational changes, and can quantify thermal stability;
3) Light scattering coupled with size-exclusion chromatography identifies aggregate masses and distinguishes conformational variants;
4) Dynamic light scattering readily detects large aggregates above 0.01% or very large
This research article describes a study using multi-angle laser light scattering to determine the molecular weights of two polystyrene polymer solutions. The molecular weights measured were 388,300±16,500 g/mol and 915,300±44,800 g/mol, which were within 2.7% of the known values for the solutions. The article provides background on static light scattering analysis and the Zimm plot method used to calculate molecular weight and radius of gyration from light scattering intensity measurements taken at varying angles.
Simona cavalu_ Adherence Properties of Acrylic Bone Cement to AluminaSimona Cavalu
The aim of this study is to investigate the adherence properties of acrylic cement based on PMMA to alumina
ceramics. These ceramics are suitable for orthopedic and dental applications, as bioinert components in prosthetic
surgery. The surface of alumina specimens were subjected to a special treatment based on acid etched followed by
two dierent uoride treatments: SnF2 and NaBF4, respectively.
SIMONA CAVALU_Biomaterials and regenerative biomedicineSimona Cavalu
This document appears to be listing the authors Iulian Vasile ANTONIAC, Simona CAVALU, and Stefan Ioan VOICU and their affiliation with Biomaterials and Regenerative Biomedicine. It seems to be citing their work but provides no other contextual information about the topic, findings, or purpose of their work within that field.
Application of uv visible spectroscopy in pharmaceutical industryFarhad Ashraf
UV-visible spectroscopy can be used for clinical and pre-clinical applications in cancer diagnosis and analysis. It allows non-invasive measurement of biomarkers like tumor oxygenation, angiogenesis, redox state, and morphology. Spectroscopy measures how light interacts with tissue via absorption and fluorescence of chromophores and fluorophores. This optical signature contains physiologically meaningful information about cancer progression and treatment response that can provide insights not available from traditional pathology. Quantitative optical techniques have the potential to improve cancer management with personalized, molecularly-informed assessments.
Abstract
A small set of amphetamines has been analyzed by gas chromatography (GC) high-resolution time-of-flight mass spectrometry (TOFMS) using a microplasma photoionization (MPPI) soft-ionization source. This plasma-based, wavelength selectable ionization source enables ionization of the test compounds and their corresponding derivatives at ~8-12 eV that is a softer alternative to electron ionization at 70 eV. Three plasma gases were used in this study: Xe plasma that emits photons at resonance lines of 9.57 eV and 8.44 eV; Kr plasma at 10.63 eV and 10.02 eV, and Ar plasma at 11.82 eV and 11.61 eV. Derivatization of the test compounds with trifluoroacetic anhydride and α-methoxy-α-(trifluoromethyl)-phenylacetyl pyrazole was evaluated because the MPPI mass spectra of the underivatized amphetamines yield primarily iminium ions, which make the identification of the test compounds by GC-TOFMS inconclusive. The MPPI mass spectra of the TFA-derivatized amphetamines yield abundant molecular ions, when using Xe as plasma gas, and enough fragment ions with the Ar plasma that can help in formula generation. The structure elucidation of two "known unknowns" designer drugs using this "tunable" soft-ionization source and a high-resolution TOF mass spectrometer is presented in this study.
PRISM Spring 2012 drug DNA binding poster Bob Rawal
This study developed a fluorescence-based method to determine the preferential DNA binding modes of drug molecules. Two nucleic acid dyes (TP3 and DAPI) that bind DNA through different modes (intercalation and minor groove binding, respectively) were used in fluorescence quenching assays with 11 drug molecules. The results identified the likelihood of intercalation for each molecule, with netropsin, berenil, pyrocatechol violet, sunset yellow, tartrazine, and new coccine preferentially binding through the minor groove and congo red, janus green, and brilliant blue preferentially binding via intercalation. NMR studies of 3 molecules corroborated the fluorescence assay findings. The method provides
Effect of doping ratio on ftir spectrum of coumarin dopedAlexander Decker
This document discusses a study on the effect of doping ratio on the FTIR spectrum of coumarin doped polystyrene films. Coumarin and polystyrene samples were prepared with different doping ratios of coumarin solution. FTIR analysis showed changes in the spectra as the doping ratio increased. Peaks associated with the coumarin dye appeared as the doping ratio increased from 10 to 60 ml, indicating the coumarin was affecting the polymer structure. The study provides information on how doping ratio can influence the spectroscopic properties of dye doped polymer films as measured by FTIR.
This document discusses using ion mobility mass spectrometry to quantify linear impurities in cyclic polylactide samples. It finds that the method was unable to accurately determine low levels of linear contamination, as cyclic ions at lower polymerization degrees were less likely to adopt the triply charged state analyzed. This led to an overestimation of linear content. Considering additional charge states or shifting ion conformations may help address this issue in future work. The document introduces the topic, experimental methods, data analysis, results showing inconsistent quantification at different polymerization degrees, and conclusions about limitations and potential improvements.
The IOSR Journal of Pharmacy (IOSRPHR) is an open access online & offline peer reviewed international journal, which publishes innovative research papers, reviews, mini-reviews, short communications and notes dealing with Pharmaceutical Sciences( Pharmaceutical Technology, Pharmaceutics, Biopharmaceutics, Pharmacokinetics, Pharmaceutical/Medicinal Chemistry, Computational Chemistry and Molecular Drug Design, Pharmacognosy & Phytochemistry, Pharmacology, Pharmaceutical Analysis, Pharmacy Practice, Clinical and Hospital Pharmacy, Cell Biology, Genomics and Proteomics, Pharmacogenomics, Bioinformatics and Biotechnology of Pharmaceutical Interest........more details on Aim & Scope).
All manuscripts are subject to rapid peer review. Those of high quality (not previously published and not under consideration for publication in another journal) will be published without delay.
Core-cladding mode resonances of long period fiber grating in concentration s...IOSR Journals
Long period fiber grating (LPFG) is photoinduced fiber device that facilitates the coupling of core
mode to different cladding modes resulting into series of transmission dips in the transmission spectrum. Here
we present LPFG chemical sensor to determine the concentration of Manganese in water at ppm level. We
fabricated LPFG of period 600μm in single mode communication fiber using 12W carbon dioxide laser
applying point by point method. The fabricated LPFG is directly used as chemical sensor since cladding modes
coupled to core mode directly come in contact with surrounding chemicals. Concentration of manganese in our
collected sample is found to be 0.0329ppm. The result is verified with sophisticated Atomic Absorption
Spectrometer (AAS).
This document summarizes an experiment on ultrafiltration and gel electrophoresis. For ultrafiltration, the goals were to understand membrane separation principles and parameters like osmotic pressure and fouling. Experiments tested filtration rate with different protein concentrations. Results showed osmotic pressure had a greater effect on mass transfer than fouling. For gel electrophoresis, the goals were to separate and measure molecular weights of pepsin and rennet using SDS-PAGE. Results showed crude pepsin, pure pepsin, and rennet-pepsin mixture were close to literature values, while rennet alone had some unexpected bands possibly from breakdown.
This document discusses the use of positron annihilation spectroscopy to analyze the free volume nanohole distribution in polymers and its correlation to the physico-chemical properties of polymers. It provides background on positron annihilation spectroscopy and how it can be used to measure free volume in polymers. The document then describes several studies that use this technique to analyze the influence of free volume properties on the swelling of polymer hydrogels, structure-property relationships in modified epoxy resins, and free volume and interfacial interactions in epoxy clay composites.
Quantitative Analysis of 30 Drugs in Whole Blood by SPE and UHPLC-TOF-MSAnnex Publishers
The document describes the development and validation of an UHPLC-TOF-MS method for the quantitative analysis of 30 drugs in whole blood. Key points:
- The method was used to simultaneously screen for and quantify 30 common drugs and drugs of abuse in blood samples.
- Samples underwent solid phase extraction, were separated via UHPLC and analyzed by TOF-MS. Extraction recoveries ranged from 41-111% and matrix effects ranged from -13% to 50%.
- Calibration curves for each drug showed good linearity. Lower limits of quantification ranged from 0.005-0.05 mg/kg. Accuracy and precision were satisfactory above the LOQ.
- The validated method allows for simultaneous screening
This document discusses a study on the synthesis, molecular structure, and quantum chemical computational interpretations of (E)-N'-(3,4-Dimethoxybenzylidene)-nicotinohydrazide monohydrate. Density functional theory calculations were performed using B3LYP and M06-2X levels of theory to optimize the geometry and study vibrational modes, natural bond orbital analysis, HOMO-LUMO analysis, molecular electrostatic potential, and thermodynamic properties. FT-IR, FT-Raman, and UV-Vis spectroscopy experiments were also carried out. The results from quantum chemical calculations showed good agreement with experimental data and provided insights into the structural stability and charge transfer interactions
Synthesis, Spectroscopic (FT-IR, FT-Raman), First Order HYPERPOLARIZABILITY a...IRJET Journal
This document discusses the synthesis, spectroscopic analysis, and density functional theory calculations of the molecule (2E)-N-phenyl-3-(4H-pyran-4-yl)prop-2-enamide (P3P2E). Fourier transform infrared and Raman spectroscopy were used to analyze the vibrational modes of the molecule experimentally. Density functional theory with B3LYP/6-311++G(d,p) was used to calculate the molecular geometry, vibrational frequencies, and other properties. The theoretical calculations showed good agreement with the experimental spectroscopic data. Frontier molecular orbital analysis and other properties like first hyperpolarizability were also calculated to understand the reactivity and nonlinear optical behavior of the
Presentation on the basic Maldi-Imaging workflow with some information on how...Diane Hatziioanou
Presentation on the basic Maldi-Imaging workflow with some information on how it works. This presentation was prepared for a group meeting and is focused almost entirely on the process of MALDI-Imaging to give the group leaders an understanding of the process as well as some important information on how to make it work well.
This document summarizes a study that synthesized and characterized the organic compound 1-(pyrazin-2-yl) piperidin-2-ol (PPOL) using computational and experimental methods. Density functional theory calculations were performed to determine the optimized geometry, vibrational frequencies, and electronic properties of PPOL. Experimental Fourier transform infrared, Raman, nuclear magnetic resonance, and UV–visible spectroscopy data were also collected and compared to the computational results. The calculations provide information on the molecular structure, vibrational modes, thermodynamic properties, and electronic structure of PPOL.
This document provides an overview of mass spectrometry. It begins with definitions and explanations of key concepts like the principle of mass spectrometry and instrumentation. It then describes various components of mass spectrometers like ion sources and types of ionization. Two ionization methods - fast atom bombardment and matrix-assisted laser desorption/ionization - are explained in detail. The document also mentions several types of mass analyzers and applications of mass spectrometry. In under 3 sentences, the document provides an introduction to mass spectrometry, explains that it involves ionizing samples and separating the ions by mass to charge ratio, and describes some common uses and components of mass spectrometry systems.
This document reports on the synthesis, molecular structure, spectroscopic characterization, and quantum chemical calculation of (2E)-1-(5-chlorothiophen-2-yl)-3-(2,3,4-trimethoxyphenyl)prop-2-en-1-one. Single crystal X-ray diffraction, FT-IR, FT-Raman, and UV–vis spectra were recorded experimentally and compared to calculations. Density functional theory was used to optimize geometry, calculate vibrational frequencies, and predict structural and spectroscopic parameters. Natural bond orbital analysis was performed to analyze stability, hyperconjugation, and charge delocalization. Time-dependent density functional theory was used to calculate electronic transitions, absorption wavelengths, and frontier
MALDI-TOF is a soft ionization technique that allows analysis of biomolecules like proteins and DNA. It works by using a laser to trigger desorption of analyte molecules that have been coated with an absorbing matrix, ionizing the molecules for analysis by mass spectrometry. The matrix facilitates the ionization process and protects the fragile biomolecules. MALDI is commonly paired with time-of-flight mass spectrometry due to TOF-MS's ability to analyze a wide range of molecular masses produced through the MALDI ionization process.
Some Biophysical Methods for Demonstrating Comparability of Conformation and ...KBI Biopharma
Sedimentation velocity, circular dichroism spectroscopy, light scattering, and dynamic light scattering are effective methods for demonstrating the comparability of protein conformation and aggregation between product lots:
1) Sedimentation velocity precisely measures sedimentation coefficients, which are highly sensitive to small conformational differences, and can detect aggregates as low as 0.2%;
2) Circular dichroism spectroscopy provides spectral fingerprints of secondary and tertiary structure that are sensitive to conformational changes, and can quantify thermal stability;
3) Light scattering coupled with size-exclusion chromatography identifies aggregate masses and distinguishes conformational variants;
4) Dynamic light scattering readily detects large aggregates above 0.01% or very large
This research article describes a study using multi-angle laser light scattering to determine the molecular weights of two polystyrene polymer solutions. The molecular weights measured were 388,300±16,500 g/mol and 915,300±44,800 g/mol, which were within 2.7% of the known values for the solutions. The article provides background on static light scattering analysis and the Zimm plot method used to calculate molecular weight and radius of gyration from light scattering intensity measurements taken at varying angles.
Simona cavalu_ Adherence Properties of Acrylic Bone Cement to AluminaSimona Cavalu
The aim of this study is to investigate the adherence properties of acrylic cement based on PMMA to alumina
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The knowledge of the key factors involved in ethiopathogenesis of the gallstones disease requires chemical, structural and elemental composition analysis
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hyaluronidase_PMMA_ cavalu SIMONA
1. JOURNAL OF OPTOELECTRONICS AND ADVANCED MATERIALS Vol. 9, No. 3, March 2007, p. 686 - 689
Adsorption behavior of hyaluronidase onto silver
nanoparticles and PMMA bone substitute
S. CAVALU*, S. CÎNTĂ PÎNZARUa, N. PEICAb, G. DAMIAN, W. KIEFERb
University of Oradea, Faculty of Medicine and Pharmacy, P-ta 1 Decembrie 10, Oradea, Romania,
aBabes-Bolyai University, Faculty of Physics, Kogalniceanu 1,RO-400084 Cluj-Napoca, Romania
bInstitut für Physikalische Chemie, Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany
Surface enhanced Raman scattering (SERS) and ATR-FTIR spectroscopy was applied in this work, in order to get
information about the adsorption behavior of the title macromolecule with respect to different surfaces. In this case, the
silver substrate can be considered as artificial substrate and the investigations regarding the mechanisms of adsorption can
be useful in order to elucidate the active site properties of this enzyme. Our purpose is to study the adsorption mechanism
of hyaluronidase onto silver nanoparticles and PMMA (polymethyl methacrylate) substrates as well as qualitative and
quantitative aspects regarding perturbations of protein secondary structure (α-helix, β-sheet and unordered structures) upon
adsorption, using deconvolution techniques.
(Received November 15, 2006; accepted December 21, 2006)
Keywords: SERS, Raman, FTIR, Hyaluronidase adsorption, Conformational change
1. Introduction
Hyaluronidase is a glycoprotein containing 5%
mannose and 2.17% glucosamine, composed by four
subunits of 14000 Da each and a total molecular weight of
55000 Da. This enzyme hydrolyzes the endo-N-acetylhexosaminic
bonds of hyaluronic acid (HA) and
chondroitin sulfuric acids A and C (but not B), primarily
to tetrasaccharide residues [1]. Recently [2] it has been
demonstrated the possibility that elevated levels of
HA/HAase could be a marker for prostate cancer
progression based on their understanding that many
tumors share similar characteristics of growth and
metastasis. By analogy with other enzymes that hydrolyze
polysaccharides, certain assumptions could be made, such
as that the two acidic amino acids, mostly two glutamic
acid residues are part of the active site. In addition, it has
been shown that the region where the polysaccharide binds
to some of these enzymes is correlated with the aromatic
side chain of several tryptophan and tyrosine residues [3].
FTIR and FT Raman spectroscopy techniques have the
potential to answer many of the questions pertaining to the
chemical detail of enzyme mechanisms and adsorption to
biomaterials. However, such application has been held
back by the twin difficulties of lack of sensitivity and
selectivity for large macromolecular complexes.
Overcoming these difficulties, surface enhanced Raman
scattering (SERS) was applied in this work, in order to get
information about the adsorption behavior of the title
macromolecule. In this case, the silver substrate can be
considered as artificial substrate and the investigations
regarding the mechanisms of adsorption can be useful in
order to elucidate the active site properties of this protein.
As the hyaluronic acid is an important constituent of
extracelular matrix of vertebrates, the adsorption
mechanism to implants materials is an essential aspect of
the cascade of biological reactions taking place at the
interface between synthetic material and biological
environment. The type and amounts of adsorbed proteins
mediate subsequent adhesion, proliferation and
differentiation of cells as well as depositing of mineral
phase. Polymethyl methacrylate (PMMA) based
biomaterials are extensively used in the past three decades
as bone substitutes and teeth due to their high
biocompatibility, bioactivity and mechanical properties,
ensured from the clinical experience [4-6].
2. Experimental
Hyaluronidase from bovine testes, type VIII, (EC
3.2.1.35), lyophilized powder, aprox.300 units/mg
(molecular weight 55 kDa- four subunits of 14 kDa each)
from Sigma Aldricht, has been used without further
purification. The stock solution of enzyme was prepared at
5 mg/ml in 0.1 M sodium phosphate buffer pH 5.3 with
0.15 M sodium chloride. Immediately prior to use it was
diluted further in the same buffer. The sodium citrate-reduced
Ag colloid has been obtained using the classical
procedure Lee-Meisel [7]. Small amount of protein
solution was dropped in 3 ml Ag colloid, the protein
concentration for SERS measurements being 10-4 mol/l
and 5.10-5mol/l, respectively. PMMA (polymethyl
methacrylate) was purchased from Stryker Howmedica
Osteonics, commercially available as BIOLOS3®. After
polymerization, small plates of PMMA were incubated for
24 hours at 37 °C in protein solution containing 2 mg/ml
in 0.1 M sodium phosphate buffer pH 5.3 with 0.15 M
sodium chloride. After drying process, the surfaces were
2. Adsorption behavior of hyaluronidase onto silver nanoparticles and PMMA bone substitute
687
analyzed by ATR FTIR spectroscopy. FT-IR spectra of the
powder hyaluronidase have been recorded using a FT-IR
Equinox 55 Bruker spectrometer with an attenuated total
reflectance (ATR) module, in the region 4000-800 cm-1,
with a scanning speed of 32 cm-1 min-1 and the spectral
width 2.0 cm-1. Curve fitting was performed by setting the
number of component bands found by second-derivative
analysis with fixed bandwidth (12 cm-1) and Gaussian
profile. The best-average fit gave the intensity of each
component band for each spectrum. The area under each
peak was used to calculate the percentage of each
component and finally used to analyze the percentage of
secondary structure components. An integrated FRA-106
S Raman module was employed for recording the FT-Raman
spectra, using an Nd:YAG laser operating at 1064
nm line for excitation. The laser power was 350 mW and
200 scans were collected for each spectrum. The detection
of the Raman signal was carried out with nitrogen cooled
Ge detector. The spectral resolution was 4 cm-1.
SERS spectra of enzyme aqueous solution in Ag
colloid were obtained using a Dylor LabRam micro-
Raman spectrometer with a 10x microscope objective. An
argon –ion laser operating at 514.5 nm with an output
power of 250 mW was employed for excitation. A number
of 10 cycles x 20 scans were accumulated. The detection
of the Raman signal has been performed with a Peltier
cooled CCD detector.
3. Results and discussion
The ATR- FT-IR spectrum of hyaluronidase
(lyophilized powder) is presented in Fig. 1 reviling the
conformationally-sensitive amide bands and the
comparison between the FT Raman and SERS spectrum
on silver nano-substrate is presented in Fig. 2. The
tentative assignments of the compared vibrational modes
are listed in Table 1, according to the related references
[8,9]
Amide I vibrations represents the in plane C=O
stretching, weakly coupled with C-N stretching and CCN
deformation. In our ATR FTIR spectrum (fig.1) is
represented by the very strong band at 1654 cm-1 while the
corresponding FT Raman is shifted to lower wavenumber
1660 cm-1 (Fig. 2) . Amide II vibrations derives mainly
from in plane N-H bending (40-60%), the C-N (18-40%)
and C-C (10%) stretching vibrations. The very strong band
at 1535 cm-1 in the ATR FTIR spectrum has a weak
correspondent at 1553 cm -1 in FT-Raman. In the SERS
spectrum, both amide I and amide II contributions are
represented through the broad and strong band ranging
from 1595 to 1550 cm-1. Amide III is a more complex
vibrational mode representing in phase combination of N-N
in plane bending and C-N stretching with contributions
from CC stretching and CO in plane bending, depending
on the details of the force field. In Fig. 1, this contribution
is represented as a weak band at 1308 cm-1, the
corresponding FT Raman is a broad band of medium
intensity ranging from 1337 to 1317 cm-1 and the SERS
corresponding is a weak to medium band at 1326 cm-1.
The stretching vibrations C-O-C, C-O and C-O-H are
selectively enhanced in the SERS spectra, emphasized by
the strong band at 1159 cm-1. The strong intensity of the
band at 219 cm-1 observed in the SERS spectra allowed the
presumption of oxygen-adsorption from the extremal
oxygen-containing functional groups from the complex
molecular structure.
0.25
0.20
0.15
0.10
0.05
0.00
amide III
amide II
amide I
3600 3200 2800 1600 1200 800
Absorbance
Wavenumber/cm-1
Fig.1. ATR- FT-IR spectrum of hyaluronidase
(lyophilized powder).
9000
6000
3000
0
2929
3244
3423
amide III
amide I
1003
Raman
3600 3200 2800 1600 1200 800 400
219
544
1159
2872
3062 2929
958
1337
1660
1449
1596
SERS
Raman intensity/arb. units
Wavenumber/cm-1
Fig. 2. Comparison between FT-Raman and SERS
spectra of hyaluronidase. Large differences can be
observed both in bands position and relative intensity.
Experimental parameters: SERS excitation 514.5 nm,
power 250 mW; Raman excitation 1064 nm, power 350 mW.
3. S. Cavalu, S. Cîntă Pînzaru, N. Peica, G. Damian, W. Kiefer
688
Table 1. Vibrational ATR FTIR, FT Raman and SERS
data (cm-1) of hyaluronidase and their proposed
assignments.
ATR-FTIR
(cm-1)
FT-RAMAN
(cm-1)
SERS
(cm-1)
Vibrational Assignment
3283 vs
3066 m
2960 m
2871 w
1654 vs
-
1535 vs
1452 m
1391 s
1308 w
1163 w
1073 w
-
-
3062
w
2929
vs
2872 sh
1660 vs
1597
w
1553
w
1449 vs
1382 w
1337 m
-
1003
m
958 w
3423
vs
3244
sh
-
2929
m
2872
sh
1633 sh
1595 vs
1550
sh
1435 vs
1371 w
1326 w
1159
vs
1031 sh
998 m
947 w
544 m
219 s
N-H stretch
O-H stretch (aqueous
colloidal Ag)
C-H stretch
Amide I, C=C
Amide II
CH2, CH3 bend, C-O-H
bend.
C-H bend
Amide III
C-O-C, C-O, C-O-H
stretch
C-O-C stretch, O-H
bend, C=O bend
C-C-O stretch
Ag-O
The ATR-FTIR spectra before and after incubation of
small plates of PMMA in hyaluronidase buffer solution
(see experimental section) are presented in Fig. 3. The
reference spectrum in Fig. 3a indicate the details of
functional groups in polymethyl methacrylate; a sharp and
intense band at 1726 cm-1is due to the presence of ester
carbonyl group stretching mode, a broad band at 1438 cm-1
due to C-H bending and the peaks in the range 1260-900
cm-1 are assigned to O-C-O, C-CH3 stretching and C-COO
vibrations . The adsorption of hyaluronidase to PMMA
surface after incubation is emphasized in Fig. 3b by the
amide I band at 1646 cm-1 and amide II at 1545 cm1.
According to literature [10,11] the shift of amide I to
lower numbers after adsorption, indicates a modification
of the secondary structure, while a decreased intensity of
the amide II band suggests an increased accessibility of
amide bond to water, which are clearly emphasized in our
spectra (Fig. 1 and Fig. 3b). Fourier deconvolution of
amide I, II and III as well as band fitting procedure were
performed in order to obtain more qualitative and
quantitative information related to the adsorption induced
conformational transitions [12,13]. Fig. 4 shows the
deconvolution of amide I band of the native (a) and
adsorbed enzyme (b) on PMMA surface. The five
components of amide I native enzyme are related to the α
helix structure (1648 cm-1), β sheet (1631 cm-1), β – turns
(1661 cm-1), aggregates (1619 cm-1) and random coil
(1685 cm-1). The related components of the adsorbed
enzyme are shifted toward higher wavenumbers and the
percentage area of each component is drastically changed.
The α helix content decreased from 32.64% to 27.68%
upon adsorption; β sheet decrease also from 36.15% to
18.8% accompanied by an increase of β- turns structure
from 9.1% to 20.8 %, the aggregates from 7% to 11.4%
and random coil from 14% to 21.8 %.
1800 1700 1600 1500 1400 1300
0.27
0.22
0.20
1800 1700 1600 1500 1400 1300
0.24
a)
Absorbance
Wavenumber/cm-1
b)
1545
1646
Absorbance
Fig. 3. a) ATR-FT-IR spectra of PMMA surface,
b) Hyaluronidase adsorbed to PMMA surface after 24 h
incubation.
Amide I native Hyaluronidase
1600 1620 1640 1660 1680 1700
1,0
0,8
0,6
0,4
0,2
0,0
abs. intensity/ arb. units
wavenumber/ cm-1
a)
1.0
0.8
0.6
0.4
0.2
0.0
Amide I adsorbed Hyaluronidase
1600 1620 1640 1660 1680 1700
abs. intensity/arb.units
wavenumber/ cm-1
b)
Fig. 4. Deconvolution spectra of amide I band of native
hyaluronidase, lyophilized (a), and adsorbed to PMMA
surface after 24 h incubation (b).
4. Adsorption behavior of hyaluronidase onto silver nanoparticles and PMMA bone substitute
689
4. Conclusions
FT-IR, FT-Raman and surface enhanced Raman
spectra of hyaluronidase adsorbed on Ag colloidal surface
have been obtained and discussed in order to get insight
into the vibrational properties of the free and adsorbed
species. SERS spectra of hyaluronidase on Ag colloidal
nanoparticles revealed well resolved Raman signal of the
chemisorbed species and allowed the presumption of
oxygen-adsorption from the extreme functional groups of
the complex molecular structure. The three N atoms
contained in the secondary amides of the structure were
sterically unable to bind to the Ag aggregates. Adsorption
behaviour of the title species was further investigated
within the PMMA bone substitute. ATR-FT-IR spectra of
PMMA surface after incubation in protein solution
indicate the adsorption of hyaluronidase to the biomaterial
surface, emphasized by the presence of amide I and II
bands.
Fourier deconvolution of amide I and band fitting
procedure were performed in order to obtain more
qualitative and quantitative information related to the
adsorption induced conformational transitions, showing
the decrease of α helix and β sheet content upon the
adsorption to biomaterial.
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*Corresponding author: scavalu@rdslink.ro