Testing of a low-cost dry cell prototype for oxyhydrogen production

This work aims to study the production of oxyhydrogen gas by a small low-cost prototype consisting of six dry cells. Firstly, a molecular composition study of the gas was carried out, presenting concentrations of 67% H2 and 28% O2. The deviation from the stoichiometric yield is discussed to be caused by water vapor production and/or oxygen dissolution in the liquid phase. Secondly, an efficiency study was done, considering the ratio between the reversible voltage of an electrolytic cell and the voltage applied to the dry cell by an external power source. Different working conditions (electrolyte concentration, 3% (w/w) of KHO and 20% (w/w) of KHO) have been tested to analyze their effect on the efficiency of the system. The results show that a lower electrolyte concentration increases the applied cell voltage, and so the necessary power input for gas production to occur, resulting in lower cell efficiency. Overall, the efficiencies are below 69.8 +/- 0.6% for the studied electrolyte concentrations and approach approximately the same value around 50% for higher powers

Preformulation and stability in biological fluids of the retrocyclin RC-101, a potential anti-HIV topical microbicide

<p>Abstract</p> <p>Background</p> <p>RC-101, a cationic peptide retrocyclin analog, has <it>in vitro </it>activity against HIV-1. Peptide drugs are commonly prone to conformational changes, oxidation and hydrolysis when exposed to excipients in a formulation or biological fluids in the body, this can affect product efficacy. We aimed to investigate RC-101 stability under several conditions including the presence of human vaginal fluids (HVF), enabling the efficient design of a safe and effective microbicide product. Stability studies (temperature, pH, and oxidation) were performed by HPLC, Circular Dichroism, and Mass Spectrometry (LC-MS/MS). Additionally, the effect of HVF on formulated RC-101 was evaluated with fluids collected from healthy volunteers, or from subjects with bacterial vaginosis (BV). RC-101 was monitored by LC-MS/MS for up to 72 h.</p> <p>Results</p> <p>RC-101 was stable at pH 3, 4, and 7, at 25 and 37°C. High concentrations of hydrogen peroxide resulted in less than 10% RC-101 reduction over 24 h. RC-101 was detected 48 h after incubation with normal HVF; however, not following incubation with HVF from BV subjects.</p> <p>Conclusions</p> <p>Our results emphasize the importance of preformulation evaluations and highlight the impact of HVF on microbicide product stability and efficacy. RC-101 was stable in normal HVF for at least 48 h, indicating that it is a promising candidate for microbicide product development. However, RC-101 stability appears compromised in individuals with BV, requiring more advanced formulation strategies for stabilization in this environment.</p

The developmental pattern of stimulus and response interference in a color-object Stroop task: an ERP study

<p>Abstract</p> <p>Background</p> <p>Several studies have shown that Stroop interference is stronger in children than in adults. However, in a standard Stroop paradigm, stimulus interference and response interference are confounded. The purpose of the present study was to determine whether interference at the stimulus level and the response level are subject to distinct maturational patterns across childhood. Three groups of children (6–7 year-olds, 8–9 year-olds, and 10–12 year-olds) and a group of adults performed a manual Color-Object Stroop designed to disentangle stimulus interference and response interference. This was accomplished by comparing three trial types. In congruent (C) trials there was no interference. In stimulus incongruent (SI) trials there was only stimulus interference. In response incongruent (RI) trials there was stimulus interference and response interference. Stimulus interference and response interference were measured by a comparison of SI with C, and RI with SI trials, respectively. Event-related potentials (ERPs) were measured to study the temporal dynamics of these processes of interference.</p> <p>Results</p> <p>There was no behavioral evidence for stimulus interference in any of the groups, but in 6–7 year-old children ERPs in the SI condition in comparison with the C condition showed an occipital P1-reduction (80–140 ms) and a widely distributed amplitude enhancement of a negative component followed by an amplitude reduction of a positive component (400–560 ms). For response interference, all groups showed a comparable reaction time (RT) delay, but children made more errors than adults. ERPs in the RI condition in comparison with the SI condition showed an amplitude reduction of a positive component over lateral parietal (-occipital) sites in 10–12 year-olds and adults (300–540 ms), and a widely distributed amplitude enhancement of a positive component in all age groups (680–960 ms). The size of the enhancement correlated positively with the RT response interference effect.</p> <p>Conclusion</p> <p>Although processes of stimulus interference control as measured with the color-object Stroop task seem to reach mature levels relatively early in childhood (6–7 years), development of response interference control appears to continue into late adolescence as 10–12 year-olds were still more susceptible to errors of response interference than adults.</p

Influence of IN‐1 antibody and acidic FGF‐fibrin glue on the response of injured corticospinal tract axons to human Schwann cell grafts

Two strategies have been shown by others to improve CST regeneration following thoracic spinal cord injury: 1) the administration of a monoclonal antibody, IN‐1, raised against a myelin‐associated, neurite growth inhibitory protein, and 2) the delivery of acidic fibroblast growth factor (aFGF) in fibrin glue in association with peripheral nerve grafts. Because autologous transplantation of human Schwann cells (SCs) is a potential strategy for CNS repair, we evaluated the ability of these two molecular agents to induce CST regeneration into human SC grafts placed to span a midthoracic spinal cord transection in the adult nude rat, a xenograft tolerant strain. IN‐1 or control (HRP) antibodies were delivered to the injury/graft region by encapsulated hybridoma cells (“IN‐1 ravioli”) or daily infusion of hybridoma culture supernatant; aFGF‐fibrin glue was placed in the same region in other animals. Anterograde tracing from the motor cortex using the dextran amine tracers, Fluororuby (FR) and biotinylated dextran amine (BDA), was performed. Thirty‐five days after grafting, the CST response was evaluated qualitatively by looking for regenerated CST fibers in or beyond grafts and quantitatively by constructing camera lucida composites to determine the sprouting index (SI), the position of the maximum termination density (MTD) rostral to the GFAP‐defined host/graft interface, and the longitudinal spread (LS) of bulbous end terminals. The latter two measures provided information about axonal die‐back. In control animals (graft only), the CST did not enter the SC graft and underwent axonal die‐back [SI = 1.4 ± 0.1, MTD = 2.0 ± 0.2, LS = 1.3 ± 0.3, (n = 3)]. Results of IN‐1 delivery from ravioli did not differ from controls, but injections of IN‐1‐containing supernatant resulted in a significant degree of sprouting but did not prevent axonal die‐back [SI = 1.9 ± 0.1, MTD = 1.5 ± 0.2, LS = 1.1 ± 0.1, (n = 7)] and traced fibers did not enter grafts. Acidic FGF dramatically reduced axonal die‐back and caused sprouting [SI = 2.0 ± 0.1 (n = 5), MTD = 0.5 ± 0.04 (n = 6), LS = 0.4 ± 0.1 (n = 6)]. Some traced fibers entered SC grafts and in 2/6 cases entered the distal interface. We conclude that 1) human SC grafts alone do not support the regeneration of injured CST fibers and do not prevent die‐back, 2) grafts plus IN‐1 antibody‐containing supernatant support some sprouting but die‐back continues, and 3) grafts plus aFGF‐fibrin glue support regeneration of some fibers into the grafts and reduce die‐back. J. Neurosci. Res. 50:888–905, 1997. © 1997 Wiley‐Liss, Inc

Combining Schwann cell bridges and olfactory-ensheathing glia grafts with chondroitinase promotes locomotor recovery after complete transection of the spinal cord

Numerous obstacles to successful regeneration of injured axons in the adult mammalian spinal cord exist. Consequently, a treatment strategy inducing axonal regeneration and significant functional recovery after spinal cord injury has to overcome these obstacles. The current study attempted to address multiple impediments to regeneration by using a combinatory strategy after complete spinal cord transection in adult rats: (1) to reduce inhibitory cues in the glial scar (chondroitinase ABC), (2) to provide a growth-supportive substrate for axonal regeneration [Schwann cells (SCs)], and (3) to enable regenerated axons to exit the bridge to re-enter the spinal cord (olfactory ensheathing glia). The combination of SC bridge, olfactory ensheathing glia, and chondroitinase ABC provided significant benefit compared with grafts only or the untreated group. Significant improvements were observed in the Basso, Beattie, and Bresnahan score and in forelimb/hindlimb coupling. This recovery was accompanied by increased numbers of both myelinated axons in the SC bridge and serotonergic fibers that grew through the bridge and into the caudal spinal cord. Although prominent descending tracts such as the corticospinal and reticulospinal tracts did not successfully regenerate through the bridge, it appeared that other populations of regenerated fibers were the driving force for the observed recovery; there was a significant correlation between numbers of myelinated fibers in the bridge and improved coupling of forelimb and hindlimb as well as open-field locomotion. Our study tests how proven experimental treatments interact in a well-established animal model, thus providing needed direction for the development of future combinatory treatment regimens

Can experiments in nonhuman primates expedite the translation of treatments for spinal cord injury in humans?

The definitive version is available at http://www.nature.com/nm/journal/v13/n5/pdf/nm1595.pdfProgress continues in developing reparative interventions to enhance recovery after experimental spinal cord injury (SCI). Much of the progress has been made with rodents, but they differ in some important ways from humans and other primates in size, neuroanatomy, neurophysiology, physiology, biochemistry, immunology, and behavior. Questions discussed were to what extent SCI rodent models present limitations for ensuring the efficacy and safety of a treatment for humans, and under what circumstances it would be advantageous or necessary to test treatments in non-human primates before or as an adjunct to clinical trials in human patients. We focus on the recovery of skilled motor control, which enables us to compare and contrast the known differences in the organization of the motor systems and in the behavior among rodents, non-human primates, and humans. In addition, we point out critical issues related to safety in the context of promoting neural connections after an injury that could lead to malfunction. Non-human primates and humans share a myriad of similarities between the structure of their motor systems and motor behavior. Therefore, the non-human primate SCI model provides many unique advantages for testing experimental effects and understanding the safeness of a reparative intervention to promote functional recovery following SCI with the appropriate relevance for humans. We conclude that non-human primate studies are critical for the timely and safe translation of selected potential interventions designed to repair neuromotor impairments in humans.This paper summarizes the discussions that took place in a workshop sponsored and organized by the Christopher Reeve Foundation (CRF).Peer reviewe

Systematic literature review comparing rapid 3-dose administration of the GSK tick-borne encephalitis vaccine with other primary immunization schedules

<p><b>Introduction</b>: Tick-borne encephalitis (TBE), which is endemic across large regions of Europe and Asia, is most effectively prevented through vaccination. Three-dose primary TBE vaccination schedules are either rapid (0,7,21-days) or conventional (0,28–84-days, 9–12-months). The second dose can also be administered at 14 days for faster priming and sero-protection).</p> <p><b>Areas covered</b>: We used a three-step selection process to identify 21 publications comparing the immunogenicity and/or safety of different schedules.</p> <p><b>Expert commentary</b>: Priming with two or three TBE vaccine doses was highly immunogenic. After conventional priming (0–28 days), 95% adults and ≥95% children had neutralization test (NT) titers ≥10 at 14 days post-dose-2 compared with 92% adults and 99% children at 21 days post-dose-3 (rapid schedule). Most subjects retained NT titers ≥10 at day 300. A single booster dose induced a strong immune response in all subjects irrespective of primary vaccination schedule or elapsed time since priming. GMT peaked at 42 days post-dose-1 (i.e., 21 days post-dose 3 [rapid-schedule], or 14–28 days post-dose-2 [conventional-schedule]), and declined thereafter. Adverse events were generally rare and declined with increasing doses. In the absence of data to recommend one particular schedule, the regimen choice will remain at the physician’s discretion, based on patient constraints and availability.</p

Impact of an online depression prevention intervention on suicide risk factors for adolescents and young adults

BackgroundAdolescent death by suicide is an emergent health crisis in the United States of America. Although many suicide prevention programs have been created to address suicide in this population, rates continue to increase. Online interventions can disseminate treatments world-wide and reach large numbers of users. Thus, the purpose of the present study was to determine the effects of CATCH-IT, an Internet-based depression prevention intervention on risk factors for suicide (i.e., suicidal ideation, hopelessness, low self-esteem and social isolation).MethodsA total of 83 participants aged 14-21 years [mean =17.5; standard deviation (SD) =2.04] consented to take part in the intervention study.ResultsResults indicated that suicidal ideation decreased from baseline to post-intervention. For those who completed the entire CATCH-IT program, the effect size was moderate (d =0.60, P&lt;0.05). For those who partially completed the program the effect size was small (d =0.22, P&lt;0.05). Interestingly, scales measuring hopelessness and social isolation were not associated with changes in suicidal ideation.ConclusionsThe findings provide initial evidence that online depression prevention programs could be related to decreased suicidal ideation, and that those who complete the entire program may benefit more than those who complete only a part of CATCH-IT