Bekkerkorsgaard4136

The aim of this study was to compare the efficacy of QMiX and ethylenediaminetetraacetic acid (EDTA) solutions with diode laser treatment in smear layer removal.

Removing the smear layer from the apical thirds of root canals is difficult, regardless of the solution used. Researchers have been improved some irrigation agitation methods to overcome this challenge, and agitation of irrigants with laser devices has become popular.

Seventy-five extracted mandibular premolars were used. After root canals were, prepared the specimens were divided into five groups (n = 15) Group 1, no irrigation; Group 2, 17% EDTA; Group 3, QMiX solution; Group 4, 17% EDTA with diode laser; and Group 5, QMiX with diode laser. The roots were split longitudinally and prepared for scanning electron microscopic (SEM) investigation. The smear layer was evaluated under × 500, × 1000, and × 2000 magnifications.

The amount of smear layer was found significantly high in the control group (p < 0.001). In the EDTA group, the amount of smear layer was significantly high at the apical thirds, and the differences among the three regions were statistically significant (p < 0.001). In the QMiX group, no difference was found between the coronal and middle thirds; however, the amount of smear layer was significantly high at the apical thirds (p < 0.001). In the EDTA plus laser and the QMiX plus laser groups, the smear layer was found significantly high at the apical thirds (p < 0.001). However, no differences were found between the coronal and middle thirds in either group.

None of the solutions completely removed the smear layer, especially at the apical thirds. Diode laser treatment with solutions decreased the amount of smear layer, without significance.

None of the solutions completely removed the smear layer, especially at the apical thirds. Diode laser treatment with solutions decreased the amount of smear layer, without significance.

A deficiency in vitamin K has been associated with increased calcium deposition and coronary artery calcification, which may lead to cardiovascular disease.

To determine the effectiveness of vitamin K supplementation as a single nutrient supplement for the primary prevention of cardiovascular disease.

We searched the following electronic databases the Cochrane Central Register of Controlled Trials (CENTRAL, Issue 8 of 12, 2014); MEDLINE (Ovid, 1946 to September week 2 2014); EMBASE Classic + EMBASE (Ovid, 1947 to September 18 2014); Science Citation Index Expanded (SCI-EXPANDED) and Conference Proceedings Citation Index, Science (CPCI-S) (both 1990 to 17 September 2014) on Web of Science (Thomson Reuters); Database of Abstracts of Reviews of Effects (DARE); Health Technology Assessment Database and Health Economics Evaluations Database (Issue 3 of 4, 2014). We searched trial registers and reference lists of reviews for further studies. We applied no language restrictions.

We included randomised controase clinical events) as it was small, short term and conducted in healthy participants.In terms of cardiovascular disease risk factors, no effects were seen for vitamin K2 on blood pressure or lipid levels, although the trial was small and findings are limited. The trial did not report any of our other secondary outcomes.

The very limited results of this review highlight the lack of evidence currently available to determine the effectiveness of vitamin K supplementation for the primary prevention of cardiovascular disease, and demonstrate the need for further high quality trials in this area.

The very limited results of this review highlight the lack of evidence currently available to determine the effectiveness of vitamin K supplementation for the primary prevention of cardiovascular disease, and demonstrate the need for further high quality trials in this area.For almost 100 years, phenoxy radical coupling has been known to proceed in nature. Because of the linkage of their molecular halves (regiochemistry) and the configuration of the biaryl axis (stereochemistry), biaryls are notoriously difficult to synthesize. Whereas the intramolecular enzymatic coupling has been elucidated in detail for several examples, the bimolecular intermolecular coupling could not be assigned to one single enzyme in the biosynthesis of axially chiral biaryls. As these transformations often take place regio- and stereoselectively, enzyme-catalyzed control is reasonable. We now report the identification and expression of fungal cytochrome P450 enzymes that catalyze regio- and stereoselective intermolecular phenol couplings. learn more The cytochrome P450 enzyme KtnC from the kotanin biosynthetic pathway of Aspergillus niger was expressed in Saccharomyces cerevisiae. The recombinant cells catalyzed the coupling of the monomeric coumarin 7-demethylsiderin both regio- and stereoselectively to the 8,8'-dimer P-orlandin, a precursor of kotanin. The sequence information obtained from the kotanin biosynthetic gene cluster was used to identify in silico a similar gene cluster in the genome of Emericella desertorum, a producer of desertorin A, the 6,8'-regioisomer of orlandin. The cytochrome P450 enzyme DesC was also expressed in S. cerevisiae and was found to regio- and stereoselectively catalyze the coupling of 7-demethylsiderin to M-desertorin A. Our results show that fungi use highly specific cytochrome P450 enzymes for regio- and stereoselective phenol coupling. The enzymatic activities of KtnC and DesC are relevant for an understanding of the mechanism of this important biosynthetic step. These results suggest that bimolecular phenoxy radical couplings in nature can be catalyzed by phenol-coupling P450 heme enzymes, which might also apply to the plant kingdom.Non-natural (synthetic) nucleobases, including 7-ethynyl- and 7-triazolyl-8-aza-7-deazaadenine, have been introduced in RNA molecules for targeted applications, and have been characterized experimentally. However, no theoretical characterization of the impact of these modifications on the structure and energetics of the corresponding H-bonded base pair is available. To fill this gap, we performed quantum mechanics calculations, starting with the analysis of the impact of the 8-aza-7-deaza modification of the adenine skeleton, and we moved then to analyze the impact of the specific substituents on the modified 8-aza-7-deazaadenine. Our analysis indicates that, despite of these severe structural modifications, the H-bonding properties of the modified base pair gratifyingly replicate those of the unmodified base pair. Similar behavior is predicted when the same skeleton modifications are applied to guanine when paired to cytosine. To stress further the H-bonding pairing in the modified adenine-uracil base pair, we explored the impact of strong electron donor and electron withdrawing substituents on the C7 position. Also in this case we found minimal impact on the base pair geometry and energy, confirming the validity of this modification strategy to functionalize RNAs without perturbing its stability and biological functionality.We demonstrate real-time quantitative phase imaging as a new optical approach for measuring the evaporation dynamics of sessile microdroplets. Quantitative phase images of various droplets were captured during evaporation. The images enabled us to generate time-resolved three-dimensional topographic profiles of droplet shape with nanometer accuracy and, without any assumptions about droplet geometry, to directly measure important physical parameters that characterize surface wetting processes. Specifically, the time-dependent variation of the droplet height, volume, contact radius, contact angle distribution along the droplet's perimeter, and mass flux density for two different surface preparations are reported. The studies clearly demonstrate three phases of evaporation reported previously pinned, depinned, and drying modes; the studies also reveal instances of partial pinning. Finally, the apparatus is employed to investigate the cooperative evaporation of the sprayed droplets. We observe and explain the neighbor-induced reduction in evaporation rate, that is, as compared to predictions for isolated droplets. In the future, the new experimental methods should stimulate the exploration of colloidal particle dynamics on the gas-liquid-solid interface.

To examine the ability of preoperative clinical characteristics to predict histological features of renal masses (RMs).

Data from consecutive patients with clinical stage I RMs treated surgically between 2010 and 2011 in the Clinical Research Office of Endourology Society (CROES) Renal Mass Registry were collected. Based on surgical histology, tumours were categorised as benign, low- or high-aggressiveness cancer. Multivariate logistic regression was used to estimate the probability of the histological group by clinical and radiographic features in the entire cohort and a subcohort of cT1a tumours. The performance of the models was studied by calibration, Nagelkerke's R(2) , and discrimination (area under the receiver operating characteristic curve).

The study cohort included 2 224 patients with a clinical stage I RM, of which 1 367 (61%) were cT1a. Benign lesions were found in 369 (16.6%), low-aggressiveness tumours in 1 156 (52%) and high-aggressiveness tumours in 699 (31.4%). Male gender, smoking his exophytic rate are associated with malignancy and high aggressiveness of clinical stage I RMs, models incorporating these characteristics have modest discriminating power, being only slightly better than the predictive ability of tumour size alone.We employed an in situ electrochemical cell in the transmission electron microscope (TEM) together with ex situ time-of-flight, secondary-ion mass spectrometry (TOF-SIMS) depth profiling, and FIB-helium ion scanning microscope (HIM) imaging to detail the structural and compositional changes associated with Na/Na(+) charging/discharging of 50 and 100 nm thin films of Sb. TOF-SIMS on a partially sodiated 100 nm Sb film gives a Na signal that progressively decreases toward the current collector, indicating that sodiation does not proceed uniformly. This heterogeneity will lead to local volumetric expansion gradients that would in turn serve as a major source of intrinsic stress in the microstructure. In situ TEM shows time-dependent buckling and localized separation of the sodiated films from their TiN-Ge nanowire support, which is a mechanism of stress-relaxation. Localized horizontal fracture does not occur directly at the interface, but rather at a short distance away within the bulk of the Sb. HIM images of FIB cross sections taken from sodiated half-cells, electrically disconnected, and aged at room temperature, demonstrate nonuniform film swelling and the onset of analogous through-bulk separation. TOF-SIMS highlights time-dependent segregation of Na within the structure, both to the film-current collector interface and to the film surface where a solid electrolyte interphase (SEI) exists, agreeing with the electrochemical impedance results that show time-dependent increase of the films' charge transfer resistance. We propose that Na segregation serves as a secondary source of stress relief, which occurs over somewhat longer time scales.