Effects of Sequence Disorder on DNA Looping and Cyclization

Effects of sequence disorder on looping and cyclization of the double-stranded DNA are studied theoretically. Both random intrinsic curvature and inhomogeneous bending rigidity are found to result in a remarkably wide distribution of cyclization probabilities. For short DNA segments, the range of the distribution reaches several orders of magnitude for even completely random sequences. The ensemble averaged values of the cyclization probability are also calculated, and the connection to the recent experiments is discussed.Comment: 8 pages, 4 figures, LaTeX; accepted to Physical Review E; v2: a substantially revised version; v3: references added, conclusions expanded, minor editorial corrections to the text; v4: a substantially revised and expanded version (total number of pages doubled); v5: new Figure 4, captions expanded, minor editorial improvements to the tex

Photoluminescence Detected Doublet Structure in the Integer and Fractional Quantum Hall Regime

We present here the results of polarized magneto-photoluminescence measurements on a high mobility single-heterojunction. The presence of a doublet structure over a large magnetic field range (2>nu>1/6) is interpreted as possible evidence for the existence of a magneto-roton minima of the charged density waves. This is understood as an indication of strong electronic correlation even in the case of the IQHE limit.Comment: submitted to Solid State Communication

A Randomized Parallel Controlled Study of the Efficacy and Safety of Lornoxicam Versus Etoricoxib after Total Knee Arthroplasty

Objectives: The aim of the study was to compare the postoperative analgesic efficacy and safety of lornoxicam versus etoricoxib for the first 48 hours after surgery. Methods: We conducted a prospective randomized controlled study on 110 patients ASAI-II scheduled for TKA under spinal anesthesia, who received either lornoxicam 8 mg PO at the end of surgery and a further 8 mg after 12 hours (Lornoxicam Group) or etoricoxib 120 mg at the end of surgery and one placebo pill after 12 hours (Etoricoxib Group). The primary outcome measure was the cumulative dose of morphine administered during the first postoperative 24 and 48 hours. Secondary outcomes were duration of analgesia and the side effects of the treatment. Results: The groups were similar in terms of demographic data. There are no significant differences between groups regarding the morphine consumption at 24 hours (36.2 ± 12 in Lornoxicam group and 34.5 ± 14.1 in Etoricoxib group) and 48 hours postoperatively (15.6 ± 12.8 in Lornoxicam group and 18 ± 12.3 in Etoricoxib group) or between the duration of analgesia (314.5 ± 70.4 in Lornoxicam group and 320.4 ± 89.2 in Etoricoxib group). Conclusion: Postoperative use of lornoxicam for 48 hours in the dose of 8 mg PO twice a day in patients undergoing TKA has an analgetic effect comparable to etoricoxib 120 mg, fewer patients experienced adverse symptoms in the etoricoxib group, but the difference was not statistically significant

Polylactic acid (PLA)/Silver-NP/VitaminE bionanocomposite electrospun nanofibers with antibacterial and antioxidant activity

Cataloged from PDF version of article.The antibacterial property of silver nanoparticles (Ag-NPs) and the antioxidant activity of Vitamin E have been combined by incorporation of these two active components within polylactic acid (PLA) nanofibers via electrospinning (PLA/Ag-NP/VitaminE nanofibers). The morphological and structural characterizations of PLA/Ag-NP/VitaminE nanofibers were performed by Scanning Electron Microscopy (SEM), Transmission Electron Microscopy and X-ray diffraction. The average fiber diameter was 140 ± 60 nm, and the size of the Ag-NP was 2.7 ± 1.5 nm. PLA/Ag-NP/VitaminE nanofibers inhibited growth of Escherichia coli, Listeria monocytogenes and Salmonella typhymurium up to 100 %. The amount of released Ag ions from the nanofibers immersed in aqueous solution was determined by Inductively Coupled Plasma Mass Spectrometry, and it has been observed that the release of Ag ions was kept approximately constant after 10 days of immersion. The antioxidant activity of PLA/Ag-NP/VitaminE nanofibers was evaluated according to DPPH (2,2-diphenyl-1-picrylhydrazyl) method and determined as 94 %. The results of the tests on fresh apple and apple juice indicated that the PLA/Ag/VitaminE nanofiber membrane actively reduced the polyphenol oxidase activity. The multifunctional electrospun PLA nanofibers incorporating Ag-NP and Vitamin E may be quite applicable in food packaging due to the extremely large surface area of nanofibers along with antibacterial and antioxidant activities. These materials could find application in food industry as a potential preservative packaging for fruits and juices. © 2014, Springer Science+Business Media Dordrecht

Current applications of 3d printing in neurosurgery

Medical implications of 3-dimensional (3D) printing technology have progressed with increasingly used especially in surgical fields. 3D printing techniques are practical and anatomically accurate methods of producing patient specific models for medical education, surgical planning, training and simulation, and implants production for the assessment and treatment of neurosurgical diseases. This article presents the main directions of 3D printing models application in neurosurgery

Charged exctions in the fractional quantum Hall regime

We study the photoluminescence spectrum of a low density ($\nu <1$) two-dimensional electron gas at high magnetic fields and low temperatures. We find that the spectrum in the fractional quantum Hall regime can be understood in terms of singlet and triplet charged-excitons. We show that these spectral lines are sensitive probes for the electrons compressibility. We identify the dark triplet charged-exciton and show that it is visible at the spectrum at $T<2$ K. We find that its binding energy scales like $e^{2}/l$, where $l$ is the magnetic length, and it crosses the singlet slightly above 15 T.Comment: 10 pages, 5 figure

Upper bounds on the first eigenvalue for a diffusion operator via Bakry-\'{E}mery Ricci curvature II

Let $L=\Delta-\nabla\varphi\cdot\nabla$ be a symmetric diffusion operator with an invariant measure $d\mu=e^{-\varphi}dx$ on a complete Riemannian manifold. In this paper we prove Li-Yau gradient estimates for weighted elliptic equations on the complete manifold with $|\nabla \varphi|\leq\theta$ and $\infty$-dimensional Bakry-\'{E}mery Ricci curvature bounded below by some negative constant. Based on this, we give an upper bound on the first eigenvalue of the diffusion operator $L$ on this kind manifold, and thereby generalize a Cheng's result on the Laplacian case (Math. Z., 143 (1975) 289-297).Comment: Final version. The original proof of Theorem 2.1 using Li-Yau gradient estimate method has been moved to the appendix. The new proof is simple and direc

The Carina dSph galaxy: where is the edge?

Recent cosmological N-body simulations suggest that current empirical estimates of tidal radii in dSphs might be underestimated by at least one order of magnitude. To constrain the plausibility of this theoretical framework, we undertook a multiband (U,B,V,I) survey of the Carina dSph. Deep B,V data of several fields located at radial distances from the Carina center ranging from 0.5 to 4.5 degrees show a sizable sample of faint blue objects with the same magnitudes and colors of old, Turn-Off stars detected across the center. We found that the (U-V,B-I) color-color plane is a robust diagnostic to split stars from background galaxies. Unfortunately, current U,I-band data are too shallow to firmly constrain the real extent of Carina.Comment: To be published on the proceedings of the XLIX meeting of the Italian Astronomical Society. Requires mem.cl

Improvement of Epitope Prediction Using Peptide Sequence Descriptors and Machine Learning

[Abstract] In this work, we improved a previous model used for the prediction of proteomes as new B-cell epitopes in vaccine design. The predicted epitope activity of a queried peptide is based on its sequence, a known reference epitope sequence under specific experimental conditions. The peptide sequences were transformed into molecular descriptors of sequence recurrence networks and were mixed under experimental conditions. The new models were generated using 709,100 instances of pair descriptors for query and reference peptide sequences. Using perturbations of the initial descriptors under sequence or assay conditions, 10 transformed features were used as inputs for seven Machine Learning methods. The best model was obtained with random forest classifiers with an Area Under the Receiver Operating Characteristics (AUROC) of 0.981 ± 0.0005 for the external validation series (five-fold cross-validation). The database included information about 83,683 peptides sequences, 1448 epitope organisms, 323 host organisms, 15 types of in vivo processes, 28 experimental techniques, and 505 adjuvant additives. The current model could improve the in silico predictions of epitopes for vaccine design. The script and results are available as a free repositor