12CO2 transition frequencies with kHz-accuracy by saturation spectroscopy in the 1.99-2.09 µm region.

Saturation spectroscopy has been used to determine the absolute frequencies of 107 ro-vibrational transitions of the two strongest 12CO2 bands of the 2 µm region. The considered 20012-00001 and 20013-00001 bands are of importance for the CO2 monitoring in our atmosphere. Lamb dips were measured using a cavity ring-down spectrometer linked to an optical frequency comb referenced to a GPS-disciplined Rb oscillator or to an ultra-stable optical frequency. The comb-coherence transfer (CCT) technique was applied to obtain a RF tunable narrow-line comb-disciplined laser source using an external cavity diode laser and a simple electro-optic modulator. This setup allows obtaining transition frequency measurements with kHz-level accuracy. The resulting accurate values of the energy levels of the 20012 and 20013 vibrational states are reproduced with a (1σ)-rms of about 1 kHz using the standard polynomial model. The two upper vibrational states appear thus to be highly isolated except for a local perturbation of the 20012 state leading to an energy shift of 15 kHz at J = 43. A recommended list of 145 transition frequencies with kHz accuracy is obtained providing secondary frequency standards across the 1.99-2.09 µm range. The reported frequencies will be valuable to constrain the zero-pressure frequencies of the considered transitions in 12CO2 retrieval from atmospheric spectra.

Neutron Spin Resonance in the Heavily Hole-Doped KFe_{2}As_{2} Superconductor.

We report high-resolution neutron scattering measurements of the low energy spin fluctuations of KFe_{2}As_{2}, the end member of the hole-doped Ba_{1-x}K_{x}Fe_{2}As_{2} family with only hole pockets, above and below its superconducting transition temperature T_{c} (∼3.5 K). Our data reveal clear spin fluctuations at the incommensurate wave vector (0.5±Î´, 0, L), (δ=0.2) (1-Fe unit cell), which exhibit L-modulation peaking at L=0.5. Upon cooling to the superconducting state, the incommensurate spin fluctuations gradually open a spin gap and form a sharp spin resonance mode. The incommensurability (2δ=0.4) of the resonance mode (∼1.2 meV) is considerably larger than the previously reported value (2δ≈0.32) at higher energies (≥∼6 meV). The determination of the momentum structure of spin fluctuation in the low energy limit allows a direct comparison with the realistic Fermi surface and superconducting gap structure. Our results point to an s-wave pairing with a reversed sign between the hole pockets near the zone center in KFe_{2}As_{2}.

Evidence for singular-phonon-induced nematic superconductivity in a topological superconductor candidate Sr0.1Bi2Se3.

Superconductivity mediated by phonons is typically conventional, exhibiting a momentum-independent s-wave pairing function, due to the isotropic interactions between electrons and phonons along different crystalline directions. Here, by performing inelastic neutron scattering measurements on a superconducting single crystal of Sr0.1Bi2Se3, a prime candidate for realizing topological superconductivity by doping the topological insulator Bi2Se3, we find that there exist highly anisotropic phonons, with the linewidths of the acoustic phonons increasing substantially at long wavelengths, but only for those along the [001] direction. This observation indicates a large and singular electron-phonon coupling at small momenta, which we propose to give rise to the exotic p-wave nematic superconducting pairing in the MxBi2Se3 (M = Cu, Sr, Nb) superconductor family. Therefore, we show these superconductors to be example systems where electron-phonon interaction can induce more exotic superconducting pairing than the s-wave, consistent with the topological superconductivity.

Ultrasmall Moment Incommensurate Spin Density Wave Order Masking a Ferromagnetic Quantum Critical Point in NbFe_{2}.

In the metallic magnet Nb_{1-y}Fe_{2+y}, the low temperature threshold of ferromagnetism can be investigated by varying the Fe excess y within a narrow homogeneity range. We use elastic neutron scattering to track the evolution of magnetic order from Fe-rich, ferromagnetic Nb_{0.981}Fe_{2.019} to approximately stoichiometric NbFe_{2}, in which we can, for the first time, characterize a long-wavelength spin density wave state burying a ferromagnetic quantum critical point. The associated ordering wave vector q_{SDW}=(0,0,l_{SDW}) is found to depend significantly on y and T, staying finite but decreasing as the ferromagnetic state is approached. The phase diagram follows a two-order-parameter Landau theory, for which all of the coefficients can now be determined. Our findings suggest that the emergence of spin density wave order cannot be attributed to band structure effects alone. They indicate a common microscopic origin of both types of magnetic order and provide strong constraints on related theoretical scenarios based on, e.g., quantum order by disorder.

Immune status in patients with subclinical forms of genitourinary tuberculosis.

The study aim was to determine whether there is a correlation between subclinical forms of genitourinary tuberculosis (GUTB) and immune status. All patients admitted to the Pneumology Clinic of the Thomayer Hospital, Prague with lung tuberculosis (LTB) were enrolled in the study. The study group consisted of 102 patients, 75 males and 27 females, median age of 46.8 years. In a previously published part of the study, 6.9 % of LTB patients were diagnosed with subclinical forms of GUTB. In the present part of the study, immune status was determined in patients with subclinical forms of GUTB by measuring circulating immunoglobulin G and CD4 T cell levels. The comparison of the immunological results did not show a statistically significant difference between the patients diagnosed with GUTB and other LTB patients..

Theoretical spin-wave dispersions in the antiferromagnetic phase AF1 of MnWO4 based on the polar atomistic model in P2.

The spin wave dispersions of the low temperature antiferromagnetic phase (AF1) MnWO4 have been numerically calculated based on the recently reported non-collinear spin configuration with two different canting angles. A Heisenberg model with competing magnetic exchange couplings and single-ion anisotropy terms could properly describe the spin wave excitations, including the newly observed low-lying energy excitation mode [Formula: see text] meV appearing at the magnetic zone centre. The spin wave dispersion and intensities are highly sensitive to two differently aligned spin-canting sublattices in the AF1 model. Thus this study reinsures the otherwise hardly provable hidden polar character in MnWO4.

Spin-Glass Ground State in a Triangular-Lattice Compound YbZnGaO_{4}.

We report on comprehensive results identifying the ground state of a triangular-lattice structured YbZnGaO_{4} as a spin glass, including no long-range magnetic order, prominent broad excitation continua, and the absence of magnetic thermal conductivity. More crucially, from the ultralow-temperature ac susceptibility measurements, we unambiguously observe frequency-dependent peaks around 0.1 K, indicating the spin-glass ground state. We suggest this conclusion holds also for its sister compound YbMgGaO_{4}, which is confirmed by the observation of spin freezing at low temperatures. We consider disorder and frustration to be the main driving force for the spin-glass phase.

Multi-band magnetotransport in exfoliated thin films of Cu x Bi2Se3.

We report magnetotransport studies in thin (<100 nm) exfoliated films of Cu x Bi2Se3 and we detect an unusual electronic transition at low temperatures. Bulk crystals show weak superconductivity with [Formula: see text] K and a possible electronic phase transition around 200 K. Following exfoliation, superconductivity is supressed and a strongly temperature dependent multi-band conductivity is observed for T < 30 K. This transition between competing conducting channels may be enhanced due to the presence of electronic ordering, and could be affected by the presence of an effective internal stress due to Cu intercalation. By fitting to the weak antilocalisation conductivity correction at low magnetic fields we confirm that the low temperature regime maintains a quantum phase coherence length [Formula: see text] nm indicating the presence of topologically protected surface states.

CRDS with a VECSEL for broad-band high sensitivity spectroscopy in the 2.3 µm window.

The integration of an industry ready packaged Sb-based Vertical-External-Cavity Surface-Emitting-Laser (VECSEL) into a Cavity Ring Down Spectrometer (CRDS) is presented. The instrument operates in the important 2.3 µm atmospheric transparency window and provides a high sensitivity (minimum detectable absorption of 9 × 10(-11) cm(-1)) over a wide spectra range. The VECSEL performances combine a large continuous tunability over 120 cm(-1) around 4300 cm(-1) together with a powerful (∼5 mW) TEM00 diffraction limited beam and linewidth at MHz level (for 1 ms of integration time). The achieved performances are illustrated by high sensitivity recordings of the very weak absorption spectrum of water vapor in the region. The developed method gives potential access to the 2-2.7 µm range for CRDS.

The self- and foreign-absorption continua of water vapor by cavity ring-down spectroscopy near 2.35 µm.

The room temperature self- and foreign-continua of water vapor have been measured near 4250 cm(-1) with a newly developed high sensitivity cavity ring down spectrometer (CRDS). The typical sensitivity of the recordings is αmin≈ 6 × 10(-10) cm(-1) which is two orders of magnitude better than previous Fourier transform spectroscopy (FTS) measurements in the spectral region. The investigated spectral interval is located in the low energy range of the important 2.1 µm atmospheric transparency window. Self-continuum cross-sections, CS, were retrieved from the quadratic dependence of the spectrum base line level measured for different water vapor pressures between 0 and 15 Torr, after subtraction of the local water monomer lines contribution calculated using HITRAN2012 line parameters. The CS values were determined with 5% accuracy for four spectral points between 4249.2 and 4257.3 cm(-1). Their values of about 3.2 × 10(-23) cm(2) molecule(-1) atm(-1) are found 20% higher than predicted by the MT_CKD V2.5 model but two times weaker than reported in the literature using FTS. The foreign-continuum was evaluated by injecting various amounts of synthetic air in the CRDS cell while keeping the initial water vapor partial pressure constant. The foreign-continuum cross-section, CF, was retrieved from a linear fit of the spectrum base line level versus the air pressure. The obtained CF values are larger by a factor of 4.5 compared to the MT_CKD values and smaller by a factor of 1.7 compared to previous FTS values. As a result, for an atmosphere at room temperature with 60% relative humidity, the foreign-continuum contribution to the water continuum near 4250 cm(-1) is found to be on the same order as the self-continuum contribution.

[An uncommon detection of Mycobacterium tuberculosis in pericardial effusion]. / Ojedinelý prípad izolovaného výskytu Mycobacterium tuberculosis v perikardiálním výpotku.

Pericardial tuberculosis is a specific pericarditis which is rarely reported in the absence of pulmonary tuberculosis. A case history is presented of a 74-year-old patient, immunocompromised as a result of kidney and liver cancer therapy. Mycobacterium tuberculosis was repeatedly recovered from pericardial effusion but not from other clinical specimens. Despite the early treatment of specific pericarditis, the patient died.

Transcranial sonography of the substantia nigra: digital image analysis.

BACKGROUND AND PURPOSE: Increased echogenicity of the substantia nigra is a typical transcranial sonography finding in Parkinson disease. Experimental software for digital analysis of the echogenic substantia nigra area has been developed. The aim of this study was to compare the evaluation of substantia nigra echogenicity by using digital analysis with a manual measurement in patients with Parkinson disease and healthy volunteers. MATERIALS AND METHODS: One hundred thirteen healthy volunteers were enrolled in the derivation cohort, and 50 healthy volunteers and 30 patients with Parkinson disease, in the validation cohort. The substantia nigra was imaged from the right and left temporal bone window by using transcranial sonography. All subjects were examined twice by using different sonographic machines by an experienced sonographer. DICOM images of the substantia nigra were encoded; then, digital analysis and manual measurement of the substantia nigra were performed. The 90th percentile of the derivation cohort values was used as a cut-point for the evaluation of the hyperechogenic substantia nigra in the validation cohort. The Spearman coefficient was used for assessment of the correlation between both measurements. The Cohen κ coefficient was used for the assessment of the correlation between both measurements and Parkinson disease diagnosis. RESULTS: The Spearman coefficient between measurements by using different machines was 0.686 for digital analysis and 0.721 for manual measurement (P < .0001). Hyperechogenic substantia nigra was detected in the same 26 (86.7%) patients with Parkinson disease by using both measurements. Cohen κ coefficients for digital analysis and manual measurement were 0.787 and 0.762, respectively (P < .0001). CONCLUSIONS: The present study showed comparable results when measuring the substantia nigra features conventionally and by using the developed software.

Magnetic phase diagrams of R2RhIn8 (R = Tb, Dy, Ho, Er and Tm) compounds.

We have grown and characterized single crystals of R(2)RhIn(8) (R=Tb, Dy, Ho, Er and Tm) compounds crystallizing in the tetragonal Ho(2)CoGa(8)-type crystal structure. Their magnetic properties were studied by specific heat and magnetization measurements. All the investigated compounds order antiferromagnetically with Néel temperatures of 43.6, 25.1, 10.9, 3.8 and 4.1 K, respectively. Magnetic phase diagrams were constructed.

[Laboratory diagnosis of mycobacterial infections]. / Laboratorní diagnostika mykobakteriálních infekcí.

Each year, tuberculosis claims nearly 2 million lives, especially in developing countries. Laboratory diagnosis of mycobacteria remains to be based on conventional approaches such as staining, culture and proportional methods for testing drug susceptibility. In recent years, new molecular methods have been proposed for mycobacterial diagnosis. Whereas the conventional methods for identification and detecting drug resistance are lengthy and cumbersome, the new assays are rapid, highly sensitive and specific and may be used for detecting resistance to antituberculosis drugs. The review describes the possibilities of laboratory diagnosis including rapid detection of mycobacteria directly from clinical specimens. For detecting latent tuberculosis, the determination of interferon gamma is important.

Specific-heat study of the Ce(1 - x)Y(x)PdAl system.

We report on specific-heat measurements of the heavy-fermion compounds Ce(1 - x)Y(x)PdAl (0 ≤ x ≤ 1) between 0.35 and 300 K and in magnetic fields up to 14 T. Ce(1 - x)Y(x)PdAl compounds crystallize in the hexagonal ZrNiAl-type structure and CePdAl orders antiferromagnetically below T(N) = 2.8 K. The specific heat measured in external magnetic fields is also consistent with the antiferromagnetic order and the phase transition to the ferromagnetic state in fields around 4 T. The temperature dependence of the magnetic specific heat in CePdAl indicates magnetic correlations far above T(N). Substitution of nonmagnetic Y for magnetic Ce ions reduces T(N) rapidly and the antiferromagnetic order vanishes around x = 0.2. The Sommerfeld coefficient γ of the electronic specific heat is temperature dependent and increases strongly at low temperatures for all Ce concentrations.

[Invasive streptococcal infections]. / Invazivní streptokokové infekce.

The severity of streptococcal infections depends upon different virulence of individual strains of its causative agent. The most important species are beta-haemolytic group A streptococci (GAS). Clinical manifestations include skin affections, respiratory tract infections and, in particular, serious systemic invasive infections. The pathogenicity of GAS is derived from cell wall components and extracellular products, especially toxins with properties of the so-called superantigens. Less invasive forms of the disease are include necrotizing fasciitis, myositis, pneumonia, sepsis without focus, arthritis, meningitis, puerperal sepsis, streptococcal toxic shock syndrome (STSS) and severe course of erysipelas and cellulitis with blood culture positive for GAS. In most cases, soft tissue infections dominate, often accompanied by chronic diseases of lower extremities in elderly patients. The other clinical forms are rather rare. In children, the condition is clearly frequently related to chickenpox. The generally accepted therapeutic management comprises comprehensive intensive care, early administration of penicillin in combination with clindamycin, and surgical intervention. The use of intravenous immunoglobulins (IVIG), elimination methods and hyperbaric oxygen are under discussion. The slight increase in cases and ineffective prevention require rapid assessment of diagnosis and adequate treatment as a protracted course of the condition is connected with a high mortality rate.

[Growth and detection of aerobic bacterial pathogens in BacT/Alert FA, BacT/Alert SA, Bactec Plus Aerobic/F and Bactec Standard Aerobic/F]. / Rust a detekce aerobních bakteriálních patogenu v lahvickách BacT/Alert FA, BacT/Alert SA, Bactec Plus Aerobic/F a Bactec Standard Aerobic/F.

The article compares the ability of detection and detection times (TTD) of aerobic bacteria in the BacT/Alert FA, BacT/Alert SA, Bactec Plus Aerobic/F and Bactec Standard Aerobic/F bottles. Compared bottles were inoculated at the same time with the identical suspension of bacterial strain. All bottles detected bacterial pathogens even in the case of very low number of inoculated bacteria. The differences of TTD were detected between the bottles of compared hemocultivation systems. Bactec Plus Aerobic/F system is faster in the detection of the members of family Enterobacteriaceae at 1-3 hours, BacT/Aert FA system is faster in the detection of coagulase-negative staphylococci. Most difference was detected at Pseudomanas stutzeri, where the detection in BacT/Alert FA bottles was at 15 hours faster in opposite of Bactec Plus Aerobic/F bottles. In the bottles without sorbent Staphylococcus aureus and Streptococcus sanqui were detected faster in the system Bactec Standard Aerobic/F. The bottles BacT/Alert SA detected faster skin corynebacteria. Detected differences have not a practical importance for the blood stream infection diagnostics.

Prevalence of extended-spectrum beta-lactamase-positive Klebsiella pneumoniae isolates in the Czech Republic.

This study focused on the prevalence and molecular biology of extended-spectrum beta-lactamase (ESBL)-positive Klebsiella pneumoniae isolates collected in the Czech Republic. Clinical material from patients hospitalised in 16 Czech hospitals in September 2004 was used to isolate K. pneumoniae strains. Strains were identified by standard identification procedures. Susceptibility of the strains to antibiotics was tested using a microdilution method. The double-disk synergy test and combination disk method were used to determine ESBL production. Molecular biology characteristics of ESBL-positive isolates were determined using genomic DNA isolation, XbaI restriction digestion and pulsed-field gel electrophoresis differentiation. The acquired restriction maps of individual isolates were compared using GelCompar II software and their relationships were determined. During the 3-week period, 483 K. pneumoniae strains causing clinically detectable diseases were isolated. Of these, 117 (24.2%) were determined to be ESBL-positive. The prevalence of ESBL-positive isolates was 38.9% in Intensive Care Units (ICUs) and 13.1% in standard wards. More than 50% of ESBL-positive isolates were treated effectively only with meropenem (98%), cefoperazone/sulbactam (61%) and amikacin (54%). Conversely, ESBL-negative isolates showed high susceptibility to all tested antibiotics (76-99%). Molecular biology analysis identified 18 clonal types containing two to six identical isolates. Seventeen clones usually contained isolates from only one hospital; isolates from two hospitals were identified only in one clone. Based on the abovementioned results, the prevalence of ESBL-positive K. pneumoniae isolates in the Czech Republic can be perceived as relatively high, especially in ICUs. Extensive spread of 'epidemic clones' within Czech hospitals and, to a limited extent, between them can be demonstrated.

[Quantitative microbiological diagnostic method of intravascular catheters infection using the BacT/Alert SA bottles]. / Metoda kvantitativní mikrobiologické diagnostiky infekce cévních katetru vyuzívající lahvicky BacT/Alert SA.

OBJECTIVE: The study describes a method of quantitatively examining vascular catheters with the aid of hemocultural devices BacT/Alert. MATERIAL AND METHODS: The amount of bacteria present on the surface of the vascular catheters was determined based on the time to detection (TTD) in hemocultural vials inoculated with bacterial suspension stirred off the catheter surface. RESULTS: A total number of 348 vascular catheters was examined with this new method. Positive cultures were detected in 26 (7.5 %) catheters. Accordance to the results of microbiological catheter examination with clinical condition of the patient was found in 93.1 %. False positivity occurred in 1.1 % (4) and false negativity in 5.7 % (20) of cases. On the basis of clinical symptoms 42 cases of catheter sepsis were diagnosed out of which 22 (52.4 %) positive microbiological quantitative examinations of vascular catheters were established. The most frequent pathogen was coagulase negative staphylococci. CONCLUSIONS: The new method, when compared with present methods, is simpler, faster and able to detect the most frequent agent of catheter infection.

[Soft tissue infection classification issues]. / K problematice klasifikace infekcí mekkých tkání.

The authors give the summary on classification of soft tissues infections. Besides aetiopathogenesis and classification, separate clinical units are mentioned with the emphasis given on necrotizing processes and basic principles of their treatment. At the end own clinical material is presented with the results of microbiological analysis at the Departments of Surgery and Orthopedic surgery in University Hospital.