Transcranial direct current stimulation - what is the evidence for its efficacy and safety?

Transcranial direct current stimulation (tDCS), a non-invasive brain stimulation technique, has emerged in the past decade as a useful investigative and therapeutic technique. A number of recent studies suggest that tDCS is safe and may be efficacious in the treatment of a variety of psychiatric and neurological disorders, including major depressive disorder, chronic neuropathic pain, and stroke. More evidence is necessary, however, before it can be recommended for general clinical application

INVESTIGATION ON DISSOLUTION PATTERN AND MATHEMATICAL MODELING OF DRUG RELEASE OF QUERCETIN BY COMPLEXATION WITH CYCLODEXTRIN NANOSPONGES

Objective: The main objective of this study was to investigate the release pattern of a poorly water-soluble drug quercetin (QU) by fabricating its cyclodextrin nanosponges. Methods: Characterization of the original QU powder and QU-loaded nanosponges was carried out by the Fourier-transformed infrared (FTIR) spectroscopy, transmission electron microscopy (TEM), and dissolution tester. The drug release pattern was subjected to various kinetic models. Results: FTIR studies confirmed the formation of inclusion complex of drug. The particle size analysis revealed that the average particle size measured by laser light scattering method is around 400–420 nm with low polydispersity index. The particle size distribution is unimodal and having a narrow range. A sufficiently high zeta potential indicates that the complexes would be stable and the tendency to agglomerate would be miniscule. TEM image revealed the porous nature of nanosponges. The dissolution of the QU nanosponges was significantly higher compared with the pure drug. Conclusion: From the kinetic study, it is apparent that the regression coefficient value closer to unity in case of Korsmeyer-Peppas model indicates that the drug release exponentially to the elapsed time. n value obtained from the Korsmeyer-Peppas plots, i.e., 0.9911 indicating non-Fickian (anomalous) transport ; thus, it projected that delivered its active ingredient by coupled diffusion and erosion

Inclusive Jet Production, Parton Distributions, and the Search for New Physics

Jet production at the Tevatron probes some of the smallest distance scales currently accessible. A gluon distribution that is enhanced at large x compared to previous determinations provides a better description of the Run 1b jet data from both CDF and D0. However, considerable uncertainty still remains regarding the gluon distribution at high x. In this paper, we examine the effects of this uncertainty, and of the remaining uncertainties in the NLO QCD theory, on jet cross section comparisons to Run 1b data. We also calculate the range of contributions still possible from any new physics. Predictions are also made for the expanded kinematic range expected for the ongoing Run 2 at the Tevatron and for the LHC.Comment: 50 pages, 31 figures, RevTe

Sequence Conservation and Functional Constraint on Intergenic Spacers in Reduced Genomes of the Obligate Symbiont Buchnera

Analyses of genome reduction in obligate bacterial symbionts typically focus on the removal and retention of protein-coding regions, which are subject to ongoing inactivation and deletion. However, these same forces operate on intergenic spacers (IGSs) and affect their contents, maintenance, and rates of evolution. IGSs comprise both non-coding, non-functional regions, including decaying pseudogenes at varying stages of recognizability, as well as functional elements, such as genes for sRNAs and regulatory control elements. The genomes of Buchnera and other small genome symbionts display biased nucleotide compositions and high rates of sequence evolution and contain few recognizable regulatory elements. However, IGS lengths are highly correlated across divergent Buchnera genomes, suggesting the presence of functional elements. To identify functional regions within the IGSs, we sequenced two Buchnera genomes (from aphid species Uroleucon ambrosiae and Acyrthosiphon kondoi) and applied a phylogenetic footprinting approach to alignments of orthologous IGSs from a total of eight Buchnera genomes corresponding to six aphid species. Inclusion of these new genomes allowed comparative analyses at intermediate levels of divergence, enabling the detection of both conserved elements and previously unrecognized pseudogenes. Analyses of these genomes revealed that 232 of 336 IGS alignments over 50 nucleotides in length displayed substantial sequence conservation. Conserved alignment blocks within these IGSs encompassed 88 Shine-Dalgarno sequences, 55 transcriptional terminators, 5 Sigma-32 binding sites, and 12 novel small RNAs. Although pseudogene formation, and thus IGS formation, are ongoing processes in these genomes, a large proportion of intergenic spacers contain functional sequences

From Structure Prediction to Genomic Screens for Novel Non-Coding RNAs

Non-coding RNAs (ncRNAs) are receiving more and more attention not only as an abundant class of genes, but also as regulatory structural elements (some located in mRNAs). A key feature of RNA function is its structure. Computational methods were developed early for folding and prediction of RNA structure with the aim of assisting in functional analysis. With the discovery of more and more ncRNAs, it has become clear that a large fraction of these are highly structured. Interestingly, a large part of the structure is comprised of regular Watson-Crick and GU wobble base pairs. This and the increased amount of available genomes have made it possible to employ structure-based methods for genomic screens. The field has moved from folding prediction of single sequences to computational screens for ncRNAs in genomic sequence using the RNA structure as the main characteristic feature. Whereas early methods focused on energy-directed folding of single sequences, comparative analysis based on structure preserving changes of base pairs has been efficient in improving accuracy, and today this constitutes a key component in genomic screens. Here, we cover the basic principles of RNA folding and touch upon some of the concepts in current methods that have been applied in genomic screens for de novo RNA structures in searches for novel ncRNA genes and regulatory RNA structure on mRNAs. We discuss the strengths and weaknesses of the different strategies and how they can complement each other

Theory of hard photoproduction

The present theoretical knowledge about photons and hard photoproduction processes, i.e. the production of jets, light and heavy hadrons, quarkonia, and prompt photons in photon-photon and photon-hadron collisions, is reviewed. Virtual and polarized photons and prompt photon production in hadron collisions are also discussed. The most important leading and next-to-leading order QCD results are compiled in analytic form. A large variety of numerical predictions is compared to data from TRISTAN, LEP, and HERA and extended to future electron and muon colliders. The sources of all relevant results are collected in a rich bibliography.Comment: Habilitationsschrift, scheduled for publication in Rev. Mod. Phys., 126 pages, 61 figure