From physiological complexity to data interactions-A case study of recordings from exercise monitoring.

The popularity of nonlinear analysis has been growing simultaneously with the technology of effort monitoring. Therefore, considering the simple methods of physiological data collection and the approaches from the information domain, we proposed integrating univariate and bivariate analysis for the rest and effort comparison. Two sessions separated by an intensive training program were studied. Nine subjects participated in the first session (S1) and seven in the second session (S2). The protocol included baseline (BAS), exercise, and recovery phase. During all phases, electrocardiogram (ECG) was recorded. For the analysis, we selected corresponding data lengths of BAS and exercise usually lasting less than 5 min. We found the utility of the differences between original data and their surrogates for sample entropy Sdiff and Kullback-Leibler divergence KLDdiff. Sdiff of heart rate variability was negative in BAS and exercise but its sensitivity for phases discrimination was not satisfactory. We studied the bivariate analysis of RR intervals and corresponding QT peaks by Interlayer Mutual Information (IMI) and average edge overlap (AVO) markers. While the IMI parameter decreases in exercise conditions, AVO increased in effort compared to BAS. These findings conclude that researchers should consider a bivariate analysis of extracted RR intervals and corresponding QT datasets, when only ECG is recorded during tests.

Stepwise Excited-state Double Proton Transfer and Fluorescence Decay Analysis.

This work considers excited state intramolecular proton transfers (ESIPT) occurred in multiple hydroxyl-containing compounds with one proton transfer site in the normal form. If several hydroxyl groups are located close to each other in a molecule, then the ESIPT process can lead to the next one. A proton donor site in the first ESIPT will be a proton acceptor during the second reaction. Therefore, a number of consecutive excited state proton transfers can occur. This work deals with the case of two successive proton transfers occurred in the molecular system. Such process is called as a stepwise excited state intramolecular double proton transfer (stepwise ESIDPT). It leads to the formation of two molecular tautomers. Therefore, fluorescence of such compounds can contain different emission bands correspond to emission of normal form and two tautomers. In this work, a rigorous analysis of fluorescence decay kinetics has been made using the model with three species, including a normal molecular form and two tautomers. The work presents theoretical framework of fluorescence decay analysis of ESIDPT process taking into account three species emission. Theoretically, the stepwise proton transfers can be consisted of more than two ESIPT reactions. It depends on molecular structure and number of involved hydroxyl groups. Here, a formal analysis of fluorescence decay kinetics has been made in the case of a stepwise process consisting of two proton transfers. Moreover, the quantum-chemical calculations have been performed in the case of scutellarein. It is a multiple hydroxyl-containing flavone and, therefore, it can be applied as a model molecule to study stepwise intramolecular proton transfers. The hypothetical scheme of ESIDPT has been proposed for this compound.

Scutellarein in organic solvents: changes in spectroscopic properties caused by solute-solvent interactions.

In this work, the spectroscopic properties of scutellarein (6-hydroxyapigenin) were studied in three organic solvents (methanol, acetonitrile and N,N-dimethylformamide) taking into account possible ionization and isomerization (tautomerization) processes. Significant visible colour changes were reported in the case of scutellarein in N,N-dimethylformamide. It was shown that isomerization processes can be one of the reasons for the observed changes in absorption spectrum, because some scutellarein isomers have an absorption band at about 623 nm while other forms of scutellarein show no absorption in this region. Moreover, spectroscopic properties were studied for cases of scutellarein in acetonitrile and methanol. The molar extinction coefficient has been found in the case of methanol solution which could be used to determine scutellarein concentration in this solvent using spectroscopic methods in future studies. The quantum-chemical calculations were performed for neutral and anionic forms and for two types of possible isomers of scutellarein in each solvent. The results help explain the experimentally observed rising absorption in the 500-750 nm wavelength range. Another important result of the quantum-chemical calculations is a prediction of excited state intramolecular proton transfer (ESIPT) in scutellarein. This result has been obtained for free molecule in vacuum and in the cases of methanol, acetonitrile and N,N-dimethylformamide solution. It was found that the excited state energy of the normal molecular form is higher than the excited state energy of the tautomer form of scutellarein.

Study of the spectroscopic properties and deprotonation of 6-bromo-2-naphthoic acid.

The present work studies the UV-Vis spectroscopic properties of 6-bromo-2-naphthoic acid (BNA) dissolved in methanol, tetrahydrofuran (THF) and ethyl acetate. It has been found that there are significant differences between the emission spectra for the samples with different concentrations of BNA in methanol. Also, the analogical changes have been observed in the case of the samples of BNA in THF and ethyl acetate which have been studied immediately after preparation and 24 h after preparation. It could be explained by deprotonation processes that take place in BNA. Moreover, it has been found that the anion formation process in BNA is more intensive in the case of methanol solvent in comparison with the cases of THF and ethyl acetate. This fact could be explained by the different polarity of these solvents. As methanol is characterized by higher polarity, the deprotonation is more intensive in the case of this solvent. To verify our assumption the quantum-chemical calculations have been also performed. It has been found that the enthalpy of dissociation (the bond-dissociation energy) is equal to 183.2, 200.2 and 205.4 kcal/mol for BNA dissolved in methanol, THF and ethyl acetate, respectively. It explains why the deprotonation process in methanol is more intensive than in THF and ethyl acetate. Thereby, the study shows that the obtained theoretical calculations are in good agreement with the experimental results.

Photophysical properties of 7-hydroxyflavanone: Quantum chemical calculations and experimental studies.

In this work the photophysical properties of 7-hydroxyflavanone in acetonitrile, ethanol and methanol have been studied. The quantum chemical calculations as well as the experimental measurements have been performed. The absorption and emission spectra have been obtained for 7-hydroxyflavanone dissolved in acetonitrile, ethanol and methanol. Emission spectrum of 7-hydroxyflavanone in studied solvents is characterized by one band with maximum at about 360 nm in the case of acetonitrile and 370 nm in the case of ethanol and methanol solvent. Moreover, it was found that normalized fluorescence spectra do not show significant dependence on excitation wavelength. It can be interpreted as evidence that just fluorophores of one species cause emission. Additionally, the molar extinction coefficients have been determined for 7-hydroxyflavanone. It is equal to about 11.6 × 103 M-1·cm-1 at 270 nm, about 11.2 × 103 M-1·cm-1 at 277 nm and about 12.0 × 103 M-1·cm-1 at 275 nm for 7-hydroxyflavanone dissolved in acetonitrile, ethanol and methanol, respectively. Moreover, the total electronic energies and dipole moments have been found using by quantum chemical calculations. The dipole moment of 7-hydroxyflavanone neutral form in the ground state equals about 2.72 D, 2.70 D and 2.71 D for the case of acetonitrile, ethanol and methanol solvents, respectively. The dipole moment in the singlet-excited state equals about 4.24 D, 4.21 D and 4.23 D for the case of acetonitrile, ethanol and methanol solvents, respectively.

[Hypercalciuria]. / Hiperkalciuria.

Hypercalciuria is the most common metabolic abnormality that causes urolithiasis. The pathogenetic mechanisms responsible for hypercalciuria include enhanced gastrointestinal absorption of calcium, increased bone resorption and/or decreased renal reabsorption of calcium; the main dietary factors promoting hypercalciuria are high dietary sodium intake and protein-rich diet. The authors discuss pathophysiology of hypercalciuria and genetic factors behind 'idiopathic hypercalciuria'. The simplified diagnostic approach to hypercalciuria is outlined herein, and available therapeutic interventions of proven efficacy in idiopathic hypercalciuria are presented as well. Dietary intervention for hypercalciuria should include reduced sodium, protein and oxalate intake. Thiazide diuretics, in conjunction with a low-sodium diet, tend to reduce urinary calcium excretion and ameliorate idiopathic hypercalciuria. Potassium citrate acts as an inhibitor of calcium stone formation in the urinary tract. A low-calcium diet should generally be avoided, as it may increase urinary oxalate excretion and actually promote stone formation. In addition, a low-calcium diet may lead to negative calcium balance in subjects with hypercalciuria, and therefore increases the risk of osteopenia.

Procalcitonin as a biomarker of acute lower respiratory tract infections.

BACKGROUND: Procalcitonin (PCT) has emerged as a promising 'acute phase' biomarker used for diagnosis of acute bacterial infections of the respiratory tract. The introduction of new sensitive PCT assays has facilitated implementation of a new clinical approach to reduce antibiotic use in acute lower respiratory tract infections (LRTIs), without compromising patient safety. OBJECTIVE: Current state of knowledge on the clinical usefulness of serum PCT measurements for the evaluation of acute LRTIs is presented herein, together with basic information on available rapid diagnostic tests for PCT measurement. METHODS: During the literature search the emphasis was on PCT use as a diagnostic, monitoring and prognostic tool for acute LRTIs. The acute LRTIs have been defined as acute bronchitis, acute exacerbations of chronic obstructive pulmonary disease or asthma, and pneumonia. Original studies involving patients with these conditions have been considered, and recent articles documenting interventional trials on PCT use for guidance of antimicrobial treatment in LRTIs have been reviewed in particular. RESULTS/CONCLUSION: When measured with sensitive and rapid assays, PCT has proved to be a good biomarker for acute bacterial LRTIs, which enables an early diagnosis, facilitates therapeutic decisions, and can inform clinicians about the course of disease and prognosis. PCT can become a particularly suitable tool for implementation in an emergency and acute medical care setting.

Left ventricular mass in patients with hyperthyroidism.

BACKGROUND: The mechanisms of increased left ventricular mass (LVM) in hyperthyroidism are complex. The aim was to determine the effects of hyperthyroidism and thyreostatic therapy on LVM regarding its interrelationship with factors responsible for the heart's hemodynamic workload. MATERIAL/METHODS: The study included 51 hyperthyroid subjects and 30 healthy controls. Left heart ventricle parameters evaluated using standard ultrasonocardiography were: left ventricular volume (end-systolic and end-diastolic), left ventricle posterior wall thickness at systole (LVPWs) and diastole (LVPWd) with the respective interventricular septal thicknesses (IVSs, IVSd), LVM, stroke volume (SV), cardiac output (CO), output-pressure index (OPI), and total peripheral resistance (TPR). Systolic (SBP) and diastolic (DBP) blood pressure, heart rate (HR), and body mass index (BMI) were investigated. Measurements were repeated after two weeks of thiamazole treatment and after attaining euthyreosis. RESULTS: Compared with controls, the hyperthyroid subjects had significant thickening of LVPWd, LVPWs, and IVSs, increased LVM, augmented SV, CO, OPI, SBP, and HR, but reduced TPR and DBP. Hyperthyroid treatment did not normalize LVM. LVM showed positive correlations with SV, CO, OPI, SBP, BMI, and serum triiodothyronine concentration and negative correlation with TPR. In multivariate regression analysis, LVM correlated with SBP, SV, and BMI (R=0.64, p<0.001). CONCLUSIONS: 1) In hyperthyroid patients, LVM is increased, mainly due to its eccentric remodeling, probably caused by volume overload; the increased LVM does not seem to be reversible despite attainment of euthyreosis. 2) The increased LVM is probably related to the heart's hemodynamic workload and reflects adaptive changes.

[Diagnostic utility of procalcitonin in community-acquired respiratory tract infections--a literature review]. / Przydatnosc diagnostyczna prokalcytoniny w pozaszpitalnych zakazeniach ukladu oddechowego--przeglad pismiennictwa.

Procalcitonin (PCT), the precursor protein of calcitonin, has proved to be a good marker of "acute phase" response in bacterial infections, particularly in severe and generalized one. The diagnostic utility of PCT in community-acquired respiratory tract infections is discussed in the article, particularly with regard to community-acquired pneumonia and the utilization of PCT as a monitoring and prognostic tool in the course of disease. Our review of the available literature on the subject enables us to state the following: (1) Serum PCT levels increased significantly only in bacterial respiratory tract infections. (2) Increases in serum PCT concentrations were related to the intensity of systemic inflammatory response in the course of disease; very high PCT levels were associated with poor prognosis. (3) Measurements of PCT concentrations were useful in clinical decision making as to antimicrobial treatment. (4) Testing the serum PCT level not only supplements the range of available markers of "acute phase" response, but also provides some additional information about ongoing systemic inflammation.