Symmetries, Currents and Conservation Laws of Self-Dual Gravity

We describe an infinite-dimensional algebra of hidden symmetries for the self-dual gravity equations. Besides the known diffeomorphism-type symmetries (affine extension of w(infinity) algebra), this algebra contains new hidden symmetries, which are an affine extension of the Lorentz rotations. The full symmetry algebra has both Kac-Moody and Virasoro-like generators, whose exponentiation maps solutions of the field equations to other solutions. Relations to problems of string theories are briefly discussed.Comment: 14 pages, LaTeX, the paper was reformatte

Plasma-deposited AgOx-doped TiOx coatings enable rapid antibacterial activity based on ROS generation

Abstract To enable a rapid-acting antibacterial mechanism without the release of biocidal substances, TiO2 catalysts have been considered based on the generation of reactive oxygen species (ROS). Doping with dissimilar metals generates electron-hole pairs with narrow band gaps promoting the production of ROS. Here, plasma technology is investigated to deposit Ag nano islets on defective TiOx films, stabilized by plasma postoxidation suppressing Ag ion release. Importantly, ROS generation is maintained upon storage in the dark yet with diminishing efficacy; however, it can be restored by exposure to visible light. The rapid-acting antibacterial properties are found to strongly correlate with ROS generation, which can even be maintained by functionalization with hydrophobic plasma polymer films. The cytocompatible coatings offer promising applications for implants and other medical devices

A single dose multi-ingredient pre-workout supplement enhances upper body resistance exercise performance

IntroductionMulti-ingredient pre-workout supplements (MIPS) are commonly used by individuals looking to enhance exercise performance and augment adaptations to training. However, the efficacy of commercially available MIPS is largely dependent on the ingredient profile, and new formulations should be investigated to determine their effectiveness. Therefore, the purpose of this study was to examine the effects of a commercially available MIPS product on performance during an upper body resistance exercise protocol.MethodsTwenty resistance-trained participants (10 men, 10 women) volunteered to complete this double-blind, placebo-controlled, crossover study consisting of 3 visits. Visit 1 consisted of body composition, 1-repetition maximum (1RM) testing, and familiarization. Visits 2 and 3 consisted of supplementation with either MIPS or placebo (PLA) 1 h prior to completion of an upper body resistance exercise workout during which power output, repetitions completed, rating of perceived exertion (RPE), and perceived recovery were recorded. Assessments of reaction time, isometric mid-thigh pull, and perceived levels of focus, energy, fatigue, and “muscle pump” were also completed before supplementation, 1 h after supplementation, and immediately after exercise.ResultsStatistical analysis revealed significant main effects of trial for reaction time (p < 0.001) and bench press peak power (p = 0.026) indicating better performance during the MIPS trial. Furthermore, total number of repetitions completed significantly increased (p = 0.003) during the MIPS (96.90 ± 21.31 repetitions) trial compared to PLA (89.50 ± 18.37 repetitions). Additionally, overall session RPE was significantly lower (p = 0.002) during the MIPS (7.6 ± 1.2) trial compared to PLA (8.3 ± 0.9).DiscussionThese findings suggest that acute supplementation with this MIPS improved upper body resistance exercise performance while reducing participant RPE. Further research should investigate the efficacy of chronic supplementation with this MIPS as the acute response provided an ergogenic benefit

1.4 nm gold nanoparticle-antibody conjugates for in situ gold immunolabelling after transduction into living human cells

Despite advances in Electron Microscopy (EM) that enable to image protein assemblies within vitreous sections of cells at nearly atomic resolution, labelling is still necessary to locate small proteins or rare complexes. Gold immunolabelling has been used for decades to localise specific proteins within cellular sections. However, current gold particle-antibody conjugates are not built with enough chemical precision to match the current resolution offered by cryo-EM methodology. Furthermore, as a close to native specimen state can only be achieved by strict preservation of a frozen hydrated state, it is required to deliver gold labelling agents into living cells prior to their vitrification. Several 1.4 nm gold nanoparticle-antibody conjugates were synthesised. Their abilities to bind to and label their corresponding epitopes within living cells after cytosolic delivery by electroporation are documented here

A novel approach to model cumulative stress:Area under the s-factor curve

OBJECTIVE: Using a large longitudinal sample of adults from the Midlife in the United States (MIDUS) study, the present study extended a recently developed hierarchical model to determine how best to model the accumulation of stressors, and to determine whether the rate of change in stressors or traditional composite scores of stressors are stronger predictors of health outcomes.METHOD: We used factor analysis to estimate a stress-factor score and then, to operationalize the accumulation of stressors we examined five approaches to aggregating information about repeated exposures to multiple stressors. The predictive validity of these approaches was then assessed in relation to different health outcomes.RESULTS: The prediction of chronic conditions, body mass index, difficulty with activities of daily living, executive function, and episodic memory later in life was strongest when the accumulation of stressors was modeled using total area under the curve (AUC) of estimated factor scores, compared to composite scores that have traditionally been used in studies of cumulative stress, as well as linear rates of change.CONCLUSIONS: Like endogenous, biological markers of stress reactivity, AUC for individual trajectories of self-reported stressors shows promise as a data reduction technique to model the accumulation of stressors in longitudinal studies. Overall, our results indicate that considering different quantitative models is critical to understanding the sequelae and predictive power of psychosocial stressors from midlife to late adulthood.</p

Neutral silicon vacancy centers in undoped diamond via surface control

Neutral silicon vacancy centers (SiV0) in diamond are promising candidates for quantum networks because of their long spin coherence times and stable, narrow optical transitions. However, stabilizing SiV0 requires high purity, boron doped diamond, which is not a readily available material. Here, we demonstrate an alternative approach via chemical control of the diamond surface. We use low-damage chemical processing and annealing in a hydrogen environment to realize reversible and highly stable charge state tuning in undoped diamond. The resulting SiV0 centers display optically detected magnetic resonance and bulk-like optical properties. Controlling the charge state tuning via surface termination offers a route for scalable technologies based on SiV0 centers, as well as charge state engineering of other defects

Complications following Bacille Calmette-Guérin Vaccination in Children under the Age of 18 Months: A Multi-center Study

Background: The BCG vaccine, used since 1921 to prevent tuberculosis (TB), considered the world's most widely used vaccine. This study aimed to investigate the frequency and the type of complications associated with Bacillus Calmette-Guérin (BCG) vaccination in Iranian children. Materials and Methods This cross-sectional study conducted for 6months among children aged up to 18 months who presented to primary health care centers in Tehran (under supervision of all three Medical Universities of Tehran) for their routine vaccinations. All children had received BCG vaccination at birth. We investigated the occurrence of BCG complications through history taking from the parents and physical examination by the study physician. Complications categorized into four major groups: local, regional, remote, and generalized and the rate of occurrence compared between the two genders. Results: Finally, 14,095 children enrolled during the study period; 574 patients (4%) had experienced at least one complication following BCG vaccination. The most common complications were local side effects observed in 304 children (2.1%); followed by lymph node involvement detected in 270 children (1.9%). Lymph node involvement was more common in males (