Effects of ascorbic acid on chemical and thermal corneal burns: A comprehensive literature review

Background: Ascorbic acid has been suggested to be effective against chemical burns. It was first tested in rabbits before being implemented in human subjects. It was proven to be useful in treatments for different conditions, such as corneal chemical and thermal burns. Herein, we aimed to review the effects of ascorbic acid in the healing of chemical and thermal corneal burns. Methods: We performed an electronic search of English literature in MEDLINE, clinicaltrials.gov, and Google Scholar, without time constraints. Articles were selected based on inclusion and exclusion criteria, using they keywords “Corneal Burn,†AND “Corneal Ulcer,†AND “Vitamin C.†This yielded 17 English language articles focused on the effect of vitamin C on chemical or thermal corneal burn-induced ulcers. Results: The 17 eligible studies that fulfilled the inclusion criteria included three retrospective, nonrandomized, comparative studies on human subjects and 14 in vivo, laboratory-based studies on rabbits (12 studies), rats (one study), as well as guinea-pigs (one study). Most studies showed benefits in using vitamin C as a prophylactic treatment to delay or stop corneal ulcer formation after chemical or thermal corneal burn. Conclusions: Vitamin C is a very basic, inexpensive prescription and can be used to treat corneal ulcers following a variety of corneal burns. This review highlights the necessity for conducting randomized controlled trials to investigate the prophylactic role of vitamin C and to determine its minimum required dose for the management of corneal ulcers after different types of corneal burns

Second Stage String Fragmentation Model

A string model, advocated by Bowler, provides a physical and intuitive picture of heavy quark fragmentation. When supplemented by an ad hoc factor of (1-z), to suppress fragmentation near z=1, it supplies an excellent fit to the data. We extend Bowler's model by accounting for the further decay of the massive mesonic states produced by the initial string breaking. We find that each subsequent string break and cascade decay beyond the first, introduces a factor of (1-z). Furthermore we find that including a finite mass for the quarks, which pop out of the vacuum and split the string, forces the first string breaking to produce massive states requiring further decay. This sequence terminates at the second stage of fragmentation where only relatively "light" heavy meson systems are formed. Thus we naturally account for the phenomenologically required factor of (1-z). We also predict that the ratio of (primary) fragments-vector/(vector plus scalar) should be .61. Our second stage string fragmentation model provides an appealing picture of heavy quark fragmentation.Comment: 15 page

Photodesorption of water ice: a molecular dynamics study

Absorption of ultraviolet radiation by water ice coating interstellar grains can lead to dissociation and desorption of the ice molecules. These processes are thought to be important in the gas-grain chemistry in molecular clouds and protoplanetary disks, but very few quantitative studies exist. We compute the photodesorption efficiencies of amorphous water ice and elucidate the mechanisms by which desorption occurs. Classical molecular dynamics calculations were performed for a compact amorphous ice surface at 10 K thought to be representative of interstellar ice. Dissociation and desorption of H2O molecules in the top six monolayers are considered following absorption into the first excited electronic state with photons in the 1300-1500 Angstrom range. The trajectories of the H and OH photofragments are followed until they escape or become trapped in the ice. The probability for H2O desorption per absorbed UV photon is 0.5-1% in the top three monolayers, then decreases to 0.03% in the next two monolayers, and is negligible deeper into the ice. The main H2O removal mechanism in the top two monolayers is through separate desorption of H and OH fragments. Removal of H2O molecules from the ice, either as H2O itself or its products, has a total probability of 2-3% per absorbed UV photon in the top two monolayers. In the third monolayer the probability is about 1% and deeper into the ice the probability of photodesorption falling to insignificant numbers. The probability of any removal of H2O per incident photon is estimated to be 3.7x10^-4, with the probability for photodesorption of intact H2O molecules being 1.4x10^-4 per incident photon. When no desorption occurs, the H and OH products can travel up to 70 and 60 Angstroms inside or on top of the surface during which they can react with other species.Comment: 12 pages, 10 figures, A&A, in pres

Current state of the art and use case description on geofencing for traffic management

This report is a result of a literature review and document gathering focused on geofence use cases specific for road traffic management. It presents geofence use cases that are trialled or to be trialled, implemented use cases, as well as conceptual and potential future use cases, showing for which type of transport they are used and how geofence zones are applied or to be applied. The report was conducted in the project GeoSence – Geofencing strategies for implementation in urban traffic management and planning. It is a Joint programme initiative (JPI) Urban Europe project funded by European Union´s Horizon 2020, under ERA-NET Cofund Urban Accessibility and Connectivity and gather project partners from Germany, Norway, Sweden and UK. The goal is to present the current state of art, and describe use cases, based on the working definition of geofencing in the project, where geofence is defined as a virtual geographically located boundary, statically or dynamically defined. The study shows that for implemented and real-traffic trial use case, geofencing has been applied within private car transport, shared micro-mobility, freight and logistics, public bus transportation and ridesourcing. For the future use cases, geofencing has been tested or conceptually developed also for automated vehicles and shared automated mobility, among others. The report summarises main use cases and find them to answering to especially four challenges in traffic management: safety, environment, efficiency, and tracking and data collection. Some of the use cases however answer to several of these challenges, such as differentiated road charging, and the use cases in micro-mobility. Further, the system and functionality of the trialled and/or implemented use cases, show different types of regulation geofence use cases can be used for, from informing, assisting, full enforcement, incentivising and penalisation. Guidelines and recommendations so far form national authorities show that the existence of joint regulation or guidelines for the use of geofencing for different use cases is low – with some exceptions. Digital representation of traffic regulation will be crucial for enabling geofencing

A lifecycle cost-driven system dynamics approach for considering additive re-manufacturing or repair in aero-engine component design

Aero-engine component design decisions should consider re-manufacturing and/or repair strategies and their impact on lifecycle cost. Existing design approaches do not account for alternative production technologies such as the use of additive manufacturing in life extension processes. This paper presents a modeling and optimization methodology for examining the impact of design decisions in the early development stage on component lifecycle cost during the in-service phase while considering the potential use of additive manufacturing in life extension strategies. Specifically, a system dynamics model is developed to assess different end-of-life scenarios. Finally, an optimization problem is formulated and solved to minimize lifecycle cost with respect to design variables related to remanufacturing

The hyperfine properties of a hydrogenated Fe/V superlattice

: We study the effect of hydrogen on the electronic, magnetic and hyperfine structures of an iron-vanadium superlattice consisting of three Fe monolayers and nine V monolayers. The contact charge density ({\rho}), the contact hyperfine field (Bhf) and the electronic field gradient (EFG) at the Fe sites for different H locations and H fillings are calculated using the first principle full-potential linear-augmented-plane-wave (FP-LAPW) method . It is found that sizeable changes in the hyperfine properties are obtained only when H is in the interface region.Comment: 6 pages, 2 figures, 3 tables, ICAME 2011 conference (Kobe, Japan

TLTF in cerebrospinal fluid for detection and staging of T. b. gambiense infection

Background: Trypanosome-derived lymphocyte triggering factor (TLTF) is a molecule released by African trypanosomes that interacts with the host immune system, resulting in increased levels of IFN-c production. Methodology/Principal findings: TLTF and anti-TLTF antibodies were assessed in sera and cerebrospinal fluid (CSF) from patients infected with Trypanosoma brucei gambiense (T. b. gambiense) in an attempt to identify alternative markers for diagnosis and stage determination of human African trypanosomiasis or sleeping sickness. Seventy-four serum and sixtyone CSF samples from patients with parasitologically confirmed infection and known disease stage along with 13 sera and CSF from uninfected controls were tested. In serum the levels of anti-TLTF antibodies were unrelated to the disease stage. In contrast, levels of anti-TLTF antibodies in CSF were higher in intermediate/late stages than in early stage disease patients. Specificity of the detected antibodies was assessed by inhibition of TLTF bioactivity as represented by its ability to induce IFN-c production. Additionally, TLTF was detected in CSF from late stage patients by Western blotting with the anti-TLTF specific monoclonal antibody MO3. Conclusions/Significance: These findings suggest a new possibility for disease diagnosis with focus on involvement of the CNS through detection of TLTF and anti-TLTF antibodies in the CSF

Novel Electron Spectroscopy of Tenuously and Weakly Bound Negative Ions

A novel method is proposed that uses very slow electron elastic collisions with atoms to identify their presence through the observation of tenuously bound (electron impact energy, E<0.1 eV) and weakly bound (E<1 eV) negative ions, formed as Regge resonances during the collisions.Comment: 4pages, 3figure