Acute coronary syndrome may develop in the background of hemodynamically non-significant coronary artery disease. It may be caused by the presence of "vulnerable plaque", which is characterized by the lipid rich core and thin fibrous cap content. NIRS - near infrared spectroscopy - is a morphological imaging method allowing determining atherosclerotic plaque cholesterol burden. Information about the chemical composition may contribute to "high risk" plaque early identification and subsequent optimal interventional strategy. The first experience with the clinical implementation of this novel method is demonstrated in a case report. Key words: acute coronary syndrome - chemogram - intravascular imaging - NIRS - vulnerable plaque.

• MeSH
• akutní koronární syndrom diagnostické zobrazování   MeSH
• aterosklerotický plát diagnostické zobrazování   MeSH
• blízká infračervená spektroskopie MeSH
• diferenciální diagnóza MeSH
• dospělí MeSH
• lidé MeSH
• rentgendiagnostika MeSH
• Check Tag
• dospělí MeSH
• lidé MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• kazuistiky MeSH

Nowadays, fragrances belong to the widely used cosmetics. Their composition is designed in a way that it evolves and changes over time. In this work, the effect of fragrances on the skin was studied - the interactions between pig skin samples and fragrances and the possibility of their detection and mutual differentiation. Non-invasive techniques of vibrational spectroscopy were used to obtain the data, namely FT-IR spectroscopy with attenuated total reflection accessory and Raman microspectroscopy. Vibrational spectra were measured within 8 h with different time intervals and after 22 h from the application of fragrance for FT-IR and Raman measurements, respectively. The obtained spectra were pre‑processed and subsequently evaluated by multivariate statistical methods. The study showed that skin treated by fragrances is well distinguishable from untreated skin, even after 22 h. In addition, it is possible to differentiate individual fragrances from each other; therefore, the use of spectroscopical techniques could be a potential tool for forensic analysis of fragrances.

• Klíčová slova
• Fragrances, Infrared spectroscopy, Multivariate statistics, Raman microspectroscopy, Skin,
• MeSH
• kosmetické přípravky * MeSH
• kůže MeSH
• odoranty MeSH
• prasata MeSH
• Ramanova spektroskopie * metody   MeSH
• spektroskopie infračervená s Fourierovou transformací metody   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• kosmetické přípravky * MeSH

The introduction to the application of (1)H MR spectroscopy for clinical and research studies of mesial temporal and extratemporal epilepsies is done. The techniques of single voxel and spectroscopic imaging are discussed and the analysis of (1)H MR spectra together with basic metabolic descriptions is presented.

• MeSH
• antikonvulziva terapeutické užití   MeSH
• elektroencefalografie MeSH
• epilepsie diagnóza   metabolismus   terapie   MeSH
• fantomy radiodiagnostické MeSH
• lidé MeSH
• magnetická rezonanční spektroskopie metody   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Názvy látek
• antikonvulziva MeSH

Depending on crystallization conditions, many organic compounds can form crystals of different structure. Their proper characterization is important, for example, in the pharmaceutical industry. While the X-ray diffractometry established as a standard method, alternative techniques are desirable for broader application flexibility and economic reasons. In the present study, Raman spectroscopy combined with the density functional calculations is suggested as a complementary method to the X-ray and other higher resolution techniques. The potential to discriminate structural differences in polymorphic crystalline forms is documented on three model compounds of industrial importance. Methacrylamide, piracetam, and 2-thiobarbituric acid were crystallized under various conditions, and their Raman spectra were recorded using 532 and 1064 nm laser excitations. X-ray diffractometry and nuclear magnetic resonance spectroscopy were used as complementary techniques to verify sample composition and structure. To interpret the observed differences in Raman frequencies and intensities, three computational strategies were explored based on single molecule, a cluster model, and a plane-wave periodic boundary conditions calculation. The single-molecule modeling was found inadequate, whereas the plane-wave approach provides the most realistic spectra. For all compounds, the differences in the Raman spectra of polymorphic forms could be unambiguously assigned to the simulations. The modeling revealed that the spectral differences were caused by the molecular structure itself as well as by crystal packing. The relative importance of these factors significantly varied across the investigated samples. Owing to its simplicity, Raman spectroscopy appears to be a promising technique capable of reliable discriminating between organic crystal polymorphic states.

• MeSH
• akrylamidy chemie   MeSH
• krystalizace MeSH
• krystalografie rentgenová MeSH
• magnetická rezonanční spektroskopie MeSH
• molekulární modely MeSH
• molekulární struktura MeSH
• piracetam chemie   MeSH
• Ramanova spektroskopie MeSH
• thiobarbituráty chemie   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• akrylamidy MeSH
• methacrylamide MeSH Prohlížeč
• piracetam MeSH
• thiobarbituráty MeSH
• thiobarbituric acid MeSH Prohlížeč

• MeSH
• lidé MeSH
• magnetická rezonanční spektroskopie metody   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• úvodní články MeSH

Skeletal muscle phosphorus-31 31 P MRS is the oldest MRS methodology to be applied to in vivo metabolic research. The technical requirements of 31 P MRS in skeletal muscle depend on the research question, and to assess those questions requires understanding both the relevant muscle physiology, and how 31 P MRS methods can probe it. Here we consider basic signal-acquisition parameters related to radio frequency excitation, TR, TE, spectral resolution, shim and localisation. We make specific recommendations for studies of resting and exercising muscle, including magnetisation transfer, and for data processing. We summarise the metabolic information that can be quantitatively assessed with 31 P MRS, either measured directly or derived by calculations that depend on particular metabolic models, and we give advice on potential problems of interpretation. We give expected values and tolerable ranges for some measured quantities, and minimum requirements for reporting acquisition parameters and experimental results in publications. Reliable examination depends on a reproducible setup, standardised preconditioning of the subject, and careful control of potential difficulties, and we summarise some important considerations and potential confounders. Our recommendations include the quantification and standardisation of contraction intensity, and how best to account for heterogeneous muscle recruitment. We highlight some pitfalls in the assessment of mitochondrial function by analysis of phosphocreatine (PCr) recovery kinetics. Finally, we outline how complementary techniques (near-infrared spectroscopy, arterial spin labelling, BOLD and various other MRI and 1 H MRS measurements) can help in the physiological/metabolic interpretation of 31 P MRS studies by providing information about blood flow and oxygen delivery/utilisation. Our recommendations will assist in achieving the fullest possible reliable picture of muscle physiology and pathophysiology.

• Klíčová slova
• 31P, MRI, exercise, metabolism, muscle, nuclear magnetic resonance spectroscopy, phosphorus MRS,
• Publikační typ
• časopisecké články MeSH

PURPOSE: Multiple data formats in the MRS community currently hinder data sharing and integration. NIfTI-MRS is proposed as a standard spectroscopy data format, implemented as an extension to the Neuroimaging informatics technology initiative (NIfTI) format. This standardized format can facilitate data sharing and algorithm development as well as ease integration of MRS analysis alongside other imaging modalities. METHODS: A file format using the NIfTI header extension framework incorporates essential spectroscopic metadata and additional encoding dimensions. A detailed description of the specification is provided. An open-source command-line conversion program is implemented to convert single-voxel and spectroscopic imaging data to NIfTI-MRS. Visualization of data in NIfTI-MRS is provided by development of a dedicated plugin for FSLeyes, the FMRIB Software Library (FSL) image viewer. RESULTS: Online documentation and 10 example datasets in the proposed format are provided. Code examples of NIfTI-MRS readers are implemented in common programming languages. Conversion software, spec2nii, currently converts 14 formats where data is stored in image-space to NIfTI-MRS, including Digital Imaging and Communications in Medicine (DICOM) and vendor proprietary formats. CONCLUSION: NIfTI-MRS aims to solve issues arising from multiple data formats being used in the MRS community. Through a single conversion point, processing and analysis of MRS data are simplified, thereby lowering the barrier to use of MRS. Furthermore, it can serve as the basis for open data sharing, collaboration, and interoperability of analysis programs. Greater standardization and harmonization become possible. By aligning with the dominant format in neuroimaging, NIfTI-MRS enables the use of mature tools present in the imaging community, demonstrated in this work by using a dedicated imaging tool, FSLeyes, for visualization.

• Klíčová slova
• MRS, MRSI, open data format, spectroscopy, visualization,
• MeSH
• informatika MeSH
• magnetická rezonanční spektroskopie MeSH
• magnetická rezonanční tomografie * MeSH
• neurozobrazování * MeSH
• software MeSH
• technologie MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH

The interaction of the central magnesium atom of chlorophyll a (Chl a) with the carbon and nitrogen backbone was investigated by magnesium K near-edge X-ray absorption fine structure (NEXAFS) spectroscopy in fluorescence detection mode. A crude extract of Chl a was measured as a 1 × 10-2 mol/L ethanol solution (which represents an upper limit of concentration without aggregation) and as dried droplets. For the first time, the investigation of Mg bound to Chl a in a liquid environment by means of X-ray absorption spectroscopy is demonstrated. A pre-edge feature in the dissolved as well as in dried Chl a NEXFAS spectra has been identified as a characteristic transition originating from Mg in the Chl a molecule. This result is confirmed by theoretical DFT calculations leading to molecular orbitals (MO) which are mainly situated on the magnesium atom and nitrogen and carbon atoms from the pyrrole rings. The description is the first referring to the MO distribution with respect to the central Mg ion of Chl a and the surrounding atoms. On this basis, new approaches for the investigations of dynamic processes of molecules in solution and structure-function relationships of photosynthetic pigments and pigment-protein complexes in their native environment can be developed.

• MeSH
• chlorofyl analogy a deriváty   chemie   MeSH
• ethanol chemie   MeSH
• hořčík chemie   MeSH
• rentgenová absorpční spektroskopie MeSH
• roztoky MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• chlorofyl MeSH
• chlorophyll a' MeSH Prohlížeč
• ethanol MeSH
• hořčík MeSH
• roztoky MeSH

Polymer brushes are frequently used as surface-tethered antifouling layers in biosensors to improve sensor surface-analyte recognition in the presence of abundant non-target molecules in complex biological samples by suppressing nonspecific interactions. However, because brushes are complex systems highly responsive to changes in their surrounding environment, studying their properties remains a challenge. Electrochemical impedance spectroscopy (EIS) is an emerging method in this context. In this mini review, we aim to elucidate the potential of EIS for investigating the physicochemical properties and structural aspects of polymer brushes. The application of EIS in brush-based biosensors is also discussed. Most common principles employed in these biosensors are presented, as well as interpretation of EIS data obtained in such setups. Overall, we demonstrate that the EIS-polymer brush pairing has a considerable potential for providing new insights into brush functionalities and designing highly sensitive and specific biosensors.

• MeSH
• biosenzitivní techniky * MeSH
• impedanční spektroskopie * MeSH
• polymery MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH
• Názvy látek
• polymery MeSH

Raman spectroscopy is an important tool to understand the structural and molecular behaviour of the liquid crystals when they undergo through different temperatures. It also helps to understand the different phase changes of the liquid crystal material as temperature changes. In this work, the structural properties of two nematic liquid crystals having relatively high clearing temperature namely 4 butylcyclohexyl-3, 5-difluoro-4- isothiocyanato biphenyl and 4-pentylcyclohexyl-3, 5-difluoro-4-isothiocyanato biphenyl are studied. The study is done using temperature dependent Raman spectroscopy. From the studies of the two compounds it has been found that the experimental values are agree well with the various functional groups and different bond assignments recorded in literature. This agreement validates the presence of different functional groups and different stretching bonds in the two studied liquid crystal compounds. Deformations of some of the peak positions of the two liquid crystal compounds have been observed with the change in phase at different temperature. Also to understand the behaviour of the Raman peak near the clearing temperatures of the liquid crystal compounds the linewidth of the different peak values at different temperature have also been studied. From the line width study, the various phase transition temperatures of the two liquid crystalline compounds can be confirmed.

• Klíčová slova
• Fluorinated liquid crystal, Temperature dependent Raman spectroscopy, Vibrational spectroscopy,
• MeSH
• bifenylové sloučeniny chemie   MeSH
• kapalné krystaly * chemie   MeSH
• Ramanova spektroskopie metody   MeSH
• teplota MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• bifenylové sloučeniny MeSH
• biphenyl MeSH Prohlížeč