Following the Nonthermal Phase Transition in Niobium Dioxide by Time-Resolved Harmonic Spectroscopy.

Photoinduced phase transitions in correlated materials promise diverse applications from ultrafast switches to optoelectronics. Resolving those transitions and possible metastable phases temporally are key enablers for these applications, but challenge existing experimental approaches. Extreme nonlinear optics can help probe phase changes, as higher-order nonlinearities have higher sensitivity and temporal resolution to band structure and lattice deformations. Here the ultrafast transition from the semiconducting to the metallic phases in polycrystalline thin-film NbO_{2} is investigated by time-resolved harmonic spectroscopy. The emission strength of all harmonic orders shows a steplike suppression when the excitation fluence exceeds a threshold (∼11-12 mJ/cm^{2}), below the fluence required for the thermal transition-a signature of the nonthermal emergence of a metallic phase within 100±20 fs. This observation is backed by full ab initio simulations as well as a 1D chain model of high-harmonic generation from both phases. Our results demonstrate femtosecond harmonic probing of phase transitions and nonthermal dynamics in solids.

Accurate equilibrium structures of methyl methacrylate and methacrylic acid by microwave spectroscopy and dispersion corrected calculations.

The rotational constants of s-trans and s-cis methyl methacrylate and methacrylic acid are determined from microwave spectra. All singly substituted heavy-atom isotopologs of the four species are measured in natural abundance. The experimental rotational constants are combined with anharmonic vibrational corrections using the Coulomb-attenuating method, Becke, three-parameter, Lee-Yang-Parr density functional with Grimme's D3 dispersion corrections and the Becke-Johnson damping function, yielding precise semi-experimental equilibrium rotational constants. These constants are used to determine semi-experimental equilibrium structures with sub-picometer accuracy, suitable for benchmarking purposes.

Density Functional Theory for Microwave Spectroscopy of Noncovalent Complexes: A Benchmark Study.

In this work, we compare the results obtained with 89 computational methods for predicting noncovalent bond lengths in weakly bound complexes. Evaluations for the performance in noncovalent interaction energies and covalent bond lengths obtained from five other data sets are included. The overall best performing density functional is the ωB97M-V method, achieving balanced results across all three categories. For noncovalent geometries, the best methods include B97M-V, B3LYP-D3(BJ) and DSD-PBEPBE-D3(BJ). The effects of systematic improvement of the density functional approximation and of dispersion corrections are also discussed.

Benchmark-Quality Semiexperimental Structural Parameters of van der Waals Complexes.

Accurate data sets including noncovalent interactions have become essential for benchmarking computational methods. However, while there is much focus on obtaining an accurate description of relative energies, reliable prediction of accurate equilibrium geometries is also important. To facilitate the benchmarking of computed geometries, the current work includes an accurate data set of semiexperimental equilibrium geometries of noncovalent complexes that can be directly compared to ab initio data. The structures are based on high-accuracy spectroscopic data, combined with vibrational corrections at the double-hybrid density functional level. The current work is designed to complement available data sets of semiexperimental geometries of small rigid molecules and ab initio geometries of complexes. The benchmark-quality data comprises 16 complexes and includes dispersion interactions, hydrogen bonding, CH/π···π interactions, and trimers. In addition to the reference data, accurate counterpoise-corrected geometries have been obtained up to the CCSD level, along with interaction energies. A short overview of the performance of computational methods, including dispersion-corrected B3LYP and B2PLYP functionals, is also included.

Blurring out hydrogen: The dynamical structure of teflic acid.

The microwave spectra of 10 teflic acid isotopologues were recorded in the frequency range of 3-25 GHz using supersonic jet-expansion Fourier transform microwave spectroscopy. Despite being asymmetric in its equilibrium structure, the delocalization of the hydrogen atom leads to a symmetric top vibrational ground state structure. In this work, we present the zero point structure obtained from the experimental rotational constants and an approach to determine the semi-experimental equilibrium structure aided by ab initio data. The Te-O bond length determined in the equilibrium structure is accurate to the picometer and can be used as a benchmark for computational methods treating relativistic effects.

[The results of five years follow-up prospective study of vaginal prolapse repaired by prolift total mesh surgery or sacrospinous fixation]. / Resení sestupu trí kompartmentu pomocí syntetického implantátu a sakrospinózní fixace: kohortová prospektivní studie s délkou follow-up peti let.

OBJECTIVE: The aim of the study is to compare the results of five years follow-up prospective study of vaginal prolapse repaired by prolift total mesh surgery or sacrospinous fixation. STUDY DESIGN: A single-center prospective, cohort study, in patients with defect grade II and more by POP-Q. SETTING: The Institute for the Care of Mather and Child; 3rd Medical Faculty Charles university, Prague. METHODS: Comparison of the preoperative state and the five years after the operation according POP Q, ICIQ-SF, PISQ 12, VAS. Comparison of intraoperative and postoperative complications. RESULTS: The study was attended by 142 patients; 75 patients underwent surgery Prolift Total and 67 patients sacrospinous fixation by Amreich Richter. On clinical examination at 5-year follow-up, we observed 15 (20.0%) case of anatomical failure in the Prolift group and 30 (44.8%) in the SSF group. Anatomic failure was defined clinically as Ba, C or Bp at the hymen or below. In assessing the overall condition before and five years after surgery using a VAS occurred in patients in the cohort Prolift Total decrease to 2.9 (± 1.9) from the original 7.8 (± 1.8). VAS in SSF group decreased after 5 years to 4.2 (± 2.7) of the original 7.8 (± 1.4). Values ICIQ-SF, analyzing the state of voiding PT group showed a decline from the original 6.7 (± 6.9) to 5.5 (± 5.3). A similar trend was evident even after the SSF. Parameters questionnaire PISQ-12 showed a positive increase from the original 28.6 (± 9.5) to 31.8 (± 7.9) points. PISQ-12 was improved from 28.7 (± 9.8) to 32.2 (± 7.5). CONCLUSION: Recurrences were observed more frequently in patients after sacrospinous fixation, while the quality of life questionnaires yielded comparable postoperative results. Quantity of intraoperative complications is low and both groups do not differ.

[Reconstruction of the posterior and central compartment with the Prolift Posterior: cohort study with a 5-year follow-up]. / Rekonstrukce defektu zadního a stredního kompartmentu pomocí kotveného implantátu Prolift Posterior: kohortová studie s petiletým follow-up.

OBJECTIVE: To analyse the results of the long-term prospective follow-up study of vaginal prolapse reconstructed using a Prolift Posterior. STUDY DESIGN: Prospective, cohort study. SETTING: Institute for the Care of Mother and Child, Prague. METHODS: Over a 5-year period (I/2006 - XII/2011) we prospectively followed a cohort of patients with posterior vaginal wall defect who underwent surgical reconstruction using a monofilament polypropylene implant Prolift Posterior (Gynecare, Ethicon, Inc., Piscataway, NJ, USA). Patients were invited for review at six weeks, three months, six months, 12 months and then yearly up to five years. Postoperative follow-up included the clinical examination and subjective evaluation using VAS, PISQ 12 and ICIQ SF. RESULTS: One hundred twenty-four women were included in the study, of which 14 (11.3%) had no prolapse surgery in their health history. There were no concomitant vaginal procedures such as hysterectomy or another implant surgery. The average operation time and blood loss were 64.25 min (min. 10, max. 205 min) and 115 ml (min. 10 ml, max. 1000 ml), respectively. Only one patient had a blood loss 1000 ml. There were no injuries of the urinary bladder or intestines during the needle insertion of the mesh. In the five-year period, the recurrence of posterior vaginal wall defect was observed in 4 cases (3.3%). The average time to the posterior vaginal wall recurrence prolapse was 19.5 months (min. 6, max. 36). De novo prolapse in the anterior compartment was observed in 25 patients (20.5%). CONCLUSION: In this prospective single centre study, we observed anatomical improvement in the implanted compartment with low recurrence rate. During five years follow-up period there was de novo anterior vaginal wall defect observed in 20.5% cases. The question of implant employment in urogynecology remain to be answered, however, our results show that implants have their position in reconstructive surgery.

Morphologic predictors of aortic expansion in chronic type B aortic dissection.

AIM: To identify morphologic factors affecting aortic expansion in patients with uncomplicated type B aortic dissections. METHODS: Computed tomography data of 24 patients (18 male; median age: 61 years), diagnosed with acute uncomplicated type B aortic dissections between 2002 and 2013, were retrospectively reviewed. All patients had at least two computed tomography angiography scans and six months of uneventful follow-up. Computed tomography scans were assessed by two independent readers with regard to presence and number of entry tears. Thoracic and abdominal aortic diameters were derived using image processing software. RESULTS: Twenty-two of 24 patients showed aortic expansion over a median computed tomography angiographic follow-up of 33.2 months. Annual rates showed an increase of 1.7 mm for total aortic diameter, 2.1 mm for the false and a decrease of -0.4 mm for the true lumen. In three patients (12.5%), aortic diameter exceeded 60 mm during follow-up, and all three patients underwent thoracic endovascular aortic repair. Patients with a maximum aortic diameter <4 cm at baseline showed a significantly higher expansion rate compared to cases with an initial maximum aortic diameter of ≥4 cm (p=0.0471). A median of two entries (range: 1-5) was recognized per patient. Presence of more than two entry tears (n = 13) was associated with faster overall diameter expansion (mean annual rates: 2.18 mm vs. 1.16 mm; p = 0.4556), and decrease of the cross-sectional surface of the true lumen over time (annual rate for > 2 entries vs. ≤2 entries: -7.8 mm2 vs. +37.5 mm2; p = 0.0369). Median size of entry tears was 12 mm (range: 2-53 mm). CONCLUSIONS: The results presented herein suggest that uncomplicated type B aortic dissection patients with more than two entry tears and/or an initial maximum aortic diameter of<4 cm are at risk for aortic dilatation and, therefore, may require stricter follow-up including the possible need for early intervention.

Two-pulse field-free orientation reveals anisotropy of molecular shape resonance.

We report the observation of macroscopic field-free orientation, i.e., more than 73% of CO molecules pointing in the same direction. This is achieved through an all-optical scheme operating at high particle densities (>10(17) cm(-3)) that combines one-color (ω) and two-color (ω+2ω) nonresonant femtosecond laser pulses. We show that the achieved orientation solely relies on the hyperpolarizability interaction as opposed to an ionization-depletion mechanism, thus, opening a wide range of applications. The achieved strong orientation enables us to reveal the molecular-frame anisotropies of the photorecombination amplitudes and phases caused by a shape resonance. The resonance appears as a local maximum in the even-harmonic emission around 28 eV. In contrast, the odd-harmonic emission is suppressed in this spectral region through the combined effects of an asymmetric photorecombination phase and a subcycle Stark effect, generic for polar molecules, that we experimentally identify.

High-harmonic probing of electronic coherence in dynamically aligned molecules.

We introduce and demonstrate a new approach to measuring coherent electron wave packets using high-harmonic spectroscopy. By preparing a molecule in a coherent superposition of electronic states, we show that electronic coherence opens previously unobserved high-harmonic-generation channels that connect distinct but coherently related electronic states. Performing the measurements in dynamically aligned nitric oxide molecules we observe the complex temporal evolution of the electronic coherence under coupling to nuclear motion. Choosing a weakly allowed transition to prepare the wave packet, we demonstrate an unprecedented sensitivity that arises from optical interference between coherent and incoherent pathways. This mechanism converts a 0.1% excitation fraction into a ∼20% signal modulation.

Direct amplitude shaping of high harmonics in the extreme ultraviolet.

We demonstrate direct amplitude shaping of high harmonics (HHs) using a reflective micromirror array based on micro-electromechanical-system (MEMS) technology. We show independent control over the intensity of each HH in the observed range (14 - 36 eV). These results are used to calculate the control achieved over the temporal structure of the attosecond pulses in the train.

High-harmonic spectroscopy of oriented OCS molecules: emission of even and odd harmonics.

We study the emission of even and odd high-harmonic orders from oriented OCS molecules. We use an intense, nonresonant femtosecond laser pulse superimposed with its phase-controlled second harmonic field to impulsively align and orient a dense sample of molecules from which we subsequently generate high-order harmonics. The even harmonics appear around the full revivals of the rotational dynamics. We demonstrate perfect coherent control over their intensity through the subcycle delay of the two-color fields. The odd harmonics are insensitive to the degree of orientation, but modulate with the degree of axis alignment, in agreement with calculated photorecombination dipole moments. We further compare the shape of the even and odd harmonic spectra with our calculations and determine the degree of orientation.

Extreme ultraviolet-excited time-resolved luminescence spectroscopy using an ultrafast table-top high-harmonic generation source.

We present a table-top extreme ultraviolet (XUV) beamline for measuring time- and frequency-resolved XUV-excited optical luminescence (XEOL) with additional femtosecond-resolution XUV transient absorption spectroscopy functionality. XUV pulses are generated via high-harmonic generation using a near-infrared pulse in a noble gas medium and focused to excite luminescence from a solid sample. The luminescence is collimated and guided into a streak camera where its spectral components are temporally resolved with picosecond temporal resolution. We time-resolve XUV-excited luminescence and compare the results to luminescence decays excited at longer wavelengths for three different materials: (i) sodium salicylate, an often used XUV scintillator; (ii) fluorescent labeling molecule 4-carbazole benzoic (CB) acid; and (iii) a zirconium metal oxo-cluster labeled with CB, which is a photoresist candidate for extreme-ultraviolet lithography. Our results establish time-resolved XEOL as a new technique to measure transient XUV-driven phenomena in solid-state samples and identify decay mechanisms of molecules following XUV and soft-x-ray excitation.

In vitro and in silico studies of interaction of synthetic 2,6,9-trisubstituted purine kinase inhibitors BPA-302, BP-21 and BP-117 with liver drug-metabolizing cytochromes P450

An evaluation of possible interactions with enzymes of drug metabolism (cytochromes P450, CYP) is an important part of studies on safety and, in general, on the properties of any drug or biologically active compound. The article is focused on the preliminary metabolic study of selected 2,6,9-trisubstituted purine kinase inhibitors with significant anticancer activities which we have developed. The compounds BP-21 and BP-117 represent strong CDK inhibitors and the compound BPA-302 was developed as selective FLT3-ITD kinase inhibitor. Here, emphasis is placed on interactions of these compounds with the nine most important forms of CYP to evaluate the possibility of inhibition of these enzymes. The possibility of their inhibitory effect was studied in vitro on selected human liver microsomal CYP enzymes. The most affected enzyme was CYP2C19. Its activity dropped to 22 % of its original value by BPA 302, to 13 % by BP-21 and to 6 % by BP-117 at the highest concentration tested (250 µmol·l(-1)). The results suggest that the metabolism of concomitantly administered drugs should not be significantly affected at lower doses. Molecular docking of BPA-302 indicated that it can bind to active site of both CYP2C19 and CYP2D6 enzymes above the heme cofactor corroborating the experimental data.

The European Exenatide study of long-term exenatide vs. glimepiride for type 2 diabetes: rationale and patient characteristics.

AIM: To describe the rationale for the European Exenatide (EUREXA) clinical study and describe the characteristics of the patient cohort. METHODS: EUREXA is a multinational study of long-term effects of add-on exenatide vs. glimepiride in patients with type 2 diabetes and failure of diet/lifestyle plus metformin monotherapy. Metformin failure was defined as hemoglobin A1c (HbA1c) > or = 6.5% and patients were overweight/obese (BMI > or = 25 to < 40 kg/m(2)). The primary end point is time to failure of combination treatment, defined from HbA1c concentration according to current criteria. At baseline, an oral glucose tolerance test (OGTT) was performed, fasting blood was taken for lipid profile and patients were randomized to add-on exenatide (5 microg b.i.d. for 4 weeks then 10 microg b.i.d.) or glimepiride (1 mg/day titrated to maximum dose). RESULTS: A total of 1039 patients were entered in the study, with mean (+/- s.d.) age 57.2 +/- 9.6 years, body mass index (BMI) 32.4 +/- 4.1 kg/m(2), duration of diabetes 5.6 +/- 4.5 years and HbA1c 7.4 +/- 0.7%. A history of cardiovascular disease (CVD) was present for 64.8% of patients overall and duration of diabetes was statistically significantly longer for patients with CVD than without (p = 0.010). Lipid abnormalities were reported for 48.9% of patients and 40.9% were taking at least one lipid-lowering medication. CONCLUSION: Patients included in the EUREXA study had early failure of glucose control with metformin and presented typical features of type 2 diabetes: overweight/obesity and high prevalence of lipid abnormalities and CVD. In this population, the effects of exenatide vs. glimepiride will be evaluated over at least 2.5 years.

Changing dopamine agonist treatment in Parkinson's disease: experiences with switching to pramipexole.

1202 patients suffering from Parkinson's disease switched from other dopamine agonists to pramipexole under open conditions either abruptly or in an overlapping, gradual manner. Mostly insufficient effectiveness motivated the switch. The investigators gave equal preference to either an abrupt or an overlapping switch to pramipexole in this observational study. There was a tendency in favour of the overlapping switch procedure in those patients who were on a relatively higher dose of a dopamine agonist before the switch. The switch was performed because the investigators expected the effect of pramipexole on tremor, motor functions and depression/anhedonia to be better compared with previous dopamine agonists. The main reasons for switching to pramipexole (anti-tremor effect, anti-depressive/anti-anhedonic effect) as given by the physicians at baseline came up to expectations. The switch to pramipexole mostly yielded further improvements irrespective of the mode of switching.

Regulation of septum formation in Aspergillus nidulans by a DNA damage checkpoint pathway.

In Aspergillus nidulans, germinating conidia undergo multiple rounds of nuclear division before the formation of the first septum. Previous characterization of temperature-sensitive sepB and sepJ mutations showed that although they block septation, they also cause moderate defects in chromosomal DNA metabolism. Results presented here demonstrate that a variety of other perturbations of chromosomal DNA metabolism also delay septum formation, suggesting that this is a general cellular response to the presence of sublethal DNA damage. Genetic evidence is provided that suggests that high levels of cyclin-dependent kinase (cdk) activity are required for septation in A. nidulans. Consistent with this notion, the inhibition of septum formation triggered by defects in chromosomal DNA metabolism depends upon Tyr-15 phosphorylation of the mitotic cdk p34nimX. Moreover, this response also requires elements of the DNA damage checkpoint pathway. A model is proposed that suggests that the DNA damage checkpoint response represents one of multiple sensory inputs that modulates p34nimX activity to control the timing of septum formation.

The Aspergillus nidulans snt genes are required for the regulation of septum formation and cell cycle checkpoints.

In Aspergillus nidulans, germinating conidia undergo multiple rounds of nuclear division before forming a septum. Previous genetic results suggest that the ability to separate nuclear division and septum formation depends upon a threshold level of activity of the cyclin-dependent kinase NIMX(cdk1). Mutations in nimX and nimT, the gene encoding the NIMX(cdk1)-activating phosphatase, have revealed that Tyr-15 phosphorylation is important for determining the timing of the formation of the first septum. Here, we describe a screen for suppressors of nimT23 (snt), designed to identify additional components of the pathway regulating septum formation. We show that a subset of the snt mutants are defective in the temporal regulation of septum formation and in cell cycle checkpoint responses. Molecular characterization of sntA shows that it is allelic to the previously described ankA gene, which encodes the NIMX(cdk1) Tyr-15 kinase. Additional experiments described in this study show that nutritional conditions modulate the timing of septum formation and alter the phenotypes displayed by the snt mutants. A model that suggests that the timing of septum formation is influenced by DNA damage and glucose availability via the sntA and sntB gene products is proposed.

Some distal limb structures develop in mice lacking Sonic hedgehog signaling.

Patterning of the limb is coordinated by the complex interplay of three signaling regions: the apical ectodermal ridge (AER), the zone of polarizing activity (ZPA), and the non-ridge limb ectoderm. Complex feedback loops exist between Shh in the ZPA, Bmps and their antagonists in the adjacent mesenchyme, Wnt7a in the dorsal ectoderm and Fgfs in the AER. In contrast to the previously reported complete absence of digits in Shh(-/-) mice, we show that one morphologically distinct digit, with a well-delineated nail and phalanges, forms in Shh(-/-) hindlimbs, while intermediate structures are severely truncated and fused. The presence of distal autopod elements is consistent with weak expression of Hoxd13 in Shh(-/-) hindlimbs. Shh(-/-) forelimbs in contrast have one distal cartilage element, a less-well differentiated nail and fused intermediate bones. Interestingly, Ihh is expressed at the tip of Shh mutant limbs and could account for formation of distal structures. In contrast to previous studies we also demonstrate that Shh signaling is required for maintenance of normal Fgf8 expression, since expression of Fgf8, unlike some other AER marker genes, is rapidly lost from anterior to posterior after E10.5, with only a small domain of Fgf8 expression remaining posteriorly. Furthermore, loss of expanded Fgf8 expression is paralleled by a collapse of the handplate. Our data show that development of most intermediate elements of the hindlimb skeleton are Shh-dependent, and that Shh signaling is required for anterior-posterior expansion of the AER in both limbs and for the subsequent branching of zeugopod and autopod elements. Finally, we show that Shh is also required for outgrowth of the limb ectoderm and thus for the formation of a distinct limb compartment.