137Cs and 40K in some traditional herbal teas collected in the mountain regions of Serbia

Herbal teas are an important part of traditional medicine in Serbia. The objective of the present study was to determine the activity concentrations of ⁴⁰K and ¹³⁷Cs in herbal tea, using the gamma spectroscopy method. The samples were collected during the period 2011–2012 in three mountain regions in Western and Central Serbia. The activity concentrations of ⁴⁰K and ¹³⁷Cs were found to be in the range of 130–1160 and 0.7–124 Bq kg^?1, respectively. The average annual effective dose equivalents from ingestion of ⁴⁰K and ¹³⁷Cs for an adult person consuming one cup of herbal tea daily were found to be 588.4–5250.2 nSv for ⁴⁰K and 4.0–706.1 nSv for ¹³⁷Cs. Our investigation showed that the herbal teas originating from Maljen, Zlatibor and Tara mountains are radiologically safe for human consumption.     

Evaluation and clinical impact of MALDI Biotyper Mycobacteria Library v6.0 for identification of nontuberculous mycobacteria by MALDI-TOF mass spectrometry

Major challenges in the identification of non-tuberculous mycobacteria (NTM) by MALDI-TOF MS include protein extraction protocol and updating of the NTM database. The aim of this study was to evaluate MALDI Biotyper Mycobacteria Library v6.0 (Bruker Daltonics GmbH, Bremen, Germany) for identification of clinical NTM isolates and its impact on clinical management. NTM isolates cultivated from clinical samples in 101 patients were identified simultaneously by PCR-reverse hybridization (Hain Lifescience GmbH, Nehren, Germany) as a routinely used reference molecular method and using MALDI Biotyper Microflex LT/SH after protein extraction. Each isolate was applied to eight spots, and mean scores were used in analysis. MALDI-TOF MS obtained correct identification to the species level for 95 (94.06%) NTM isolates. The majority of correctly identified isolates (92/95; 96.84%) were identified with high-confidence score of ≥1.80 and only 3.16% (3/95) with a score of <1.80. Mean value ± SD of RGM NTM isolates (2.127 ± 0.172) was statistically significant higher in comparison to SGM NTM isolates (2.027 ± 0.142) with a p value of 0.007. In comparison to PCR-reverse hybridization, discordant identification results by MALDI-TOF MS were found in six (6/101; 5.94%) NTM isolates for which clinical data were analyzed. We demonstrated a high confidence NTM identifications using Mycobacterium Library v 6.0 on routine clinical isolates. This is the first study that analyzed MALDI-TOF MS identification results of NTM isolates in the context of clinical data, and it showed that MALDI-TOF MS with its updated databases could help clarify the epidemiology, clinical characteristics, and course of infections caused by less frequent NTM species.     

Production of porous silica microparticles by membrane emulsification

A method for the production of near-monodispersed spherical silica particles with controllable porosity based on the formation of uniform emulsion droplets using membrane emulsification is described. A hydrophobic metal membrane with a 15 μm pore size and 200 μm pore spacing was used to produce near-monodispersed droplets, with a mean size that could be controlled between 65 and 240 μm containing acidified sodium silicate solution (with 4 and 6 wt % SiO(2)) in kerosene. After drying and shrinking, the final silica particles had a mean size in the range between 30 and 70 μm. The coefficient of variation for both the droplets and the particles did not exceed 35%. The most uniform particles had a mean diameter of 40 μm and coefficient of variation of 17%. By altering the pH of the sodium silicate solution and aging the gel particles in water or acetone, the internal structure of the silica particles was successfully modified, and both micro- and mesoporous near-monodispersed spherical particles were produced with an average internal pore size between 1 and 6 nm and an average surface area between 360 and 750 m(2) g(-1). A material balance and particle size analysis provided identical values for the internal voidage of the particles, when compared to the voidage as determined by BET analysis.     

A larger GL2 large sieve in the level aspect

In this paper we study the orthogonality of Fourier coefficients of holomorphic cusp forms in the sense of large sieve inequality. We investigate the family of GL ₂ cusp forms modular with respect to the congruence subgroups Γ₁(q), with additional averaging over the levels q ∼ Q. We obtain the orthogonality in the range N ≪ Q ^2−δ for any δ > 0, where N is the length of linear forms in the large sieve.     

The the uniform mean-square ergodic theorem for wide sense stationary processes

It is shown that the uniform mean-square ergodic theorem holds for the family of wide sense stationary sequences, as soon as the random process with orthogonal increments, which corresponds to the orthogonal stochastic measure generated by means of the spectral representation theorem, is of bounded variation and uniformly continuous at zero in a mean-square sense. The converse statement is also shown to be valid, whenever the process is sufficiently rich. The method of proof relies upon the spectral representation theorem, integration by parts formula, and estimation of the asymptotic behaviour of total variation of the underlying trigonometric functions. The result extends and generalizes to provide the uniform mean-square ergodic theorem for families of wide sense stationary processes     

Effects of Cardiac Resynchronization Therapy on Cardio-Respiratory Coupling

In this study, the effect of cardiac resynchronization therapy (CRT) on the relationship between the cardiovascular and respiratory systems in heart failure subjects was examined for the first time. We hypothesized that alterations in cardio-respiratory interactions, after CRT implantation, quantified by signal complexity, could be a marker of a favorable CRT response. Sample entropy and scaling exponents were calculated from synchronously recorded cardiac and respiratory signals 20 min in duration, collected in 47 heart failure patients at rest, before and 9 months after CRT implantation. Further, cross-sample entropy between these signals was calculated. After CRT, all patients had lower heart rate and CRT responders had reduced breathing frequency. Results revealed that higher cardiac rhythm complexity in CRT non-responders was associated with weak correlations of cardiac rhythm at baseline measurement over long scales and over short scales at follow-up recording. Unlike CRT responders, in non-responders, a significant difference in respiratory rhythm complexity between measurements could be consequence of divergent changes in correlation properties of the respiratory signal over short and long scales. Asynchrony between cardiac and respiratory rhythm increased significantly in CRT non-responders during follow-up. Quantification of complexity and synchrony between cardiac and respiratory signals shows significant associations between CRT success and stability of cardio-respiratory coupling.     

Could X-Ray Analysis Explain for the Differing Antimicrobial and Antioxidant Activity of Two 2-Arylamino-3-Nitro-Coumarins?

Abstract  

X-Ray analyses of 4-(naphthalen-1-ylamino)-3-nitro-chromen-2-one and 3-nitro-4-phenylamino-chromen-2-one showed that the mentioned compounds crystallize in the space groups P1- (triclinic crystal system; unit cell parameters: a = 8.087(2) ?, b = 9.241(3) ?, c = 10.911(3) ?, α = 93.77(3)°, β = 102.51(3)°, γ = 106.44(2)°, V = 756.4(4) ?³ and Z = 2) and P2₁2₁2₁ (orthorhombic crystal system; unit cell parameters: a = 4.9274(9) ?, b = 14.725(3) ?, c = 17.866(4) ?, α = β = γ = 90°, V = 1296.3(5) ?³ and Z = 4), respectively. The analyses of crystal structures and gas phase conformations, inferred from single X-ray crystallographic and molecular modeling experiments, respectively, showed that the changes in π delocalization of the farmacoactive formal 3-amino-2-nitro-acrylic acid derivatives might explain the observed significant difference of the antimicrobial and antioxidant activities and spectral properties of two 4-arylamino-3-nitro-coumarin derivatives.     

Repeated passing principle for propagation in optical resonators

In this paper we make comparison between a well-known theoretical model of light propagation through racetrack resonator and experimentally obtained results. Observed differences are studied and some original modifications are made in the existing model so as to achieve better alignment with experiment. The influence of several geometric parameters on racetrack’s response is used for further adjustments to be performed. This procedure opens up the possibility to estimate the free spectral range and resonant wavelength for different geometric parameters and consequently to predict resonator functionality and working conditions, as well as functionality of complex photonic devices based on resonant structures.     

Nematic,smectic and columnar phases of main-chain liquid crystal polyethers

A number of interesting thermotropic mesophases and transitions occur in main-chain polyethers and copolyethers based on aliphatic spacers and various semi-flexible mesogens of the general 1-(4'-hydroxyphenyl)-2-(2-R-4-hydroxyphenyl)ethane (RBPE) or 1-(4'-hydroxybiphenyl-4-yl)-2-(4-hydroxyphenyl)propane (TPP) type. The unusual effects described here are (i) nematic-nematic transition, (ii) smectic-B (crystal-B) phase and its shear-induced orientation, (iii) calamitic columnar phase, and (iv) nematic-columnar phase sequence.