A comparison between the free grafting of sliced and intact muscles in the rat

Transverse slicing is a new technique whereby a mammalian muscle can be freely grafted with success. This method eliminates contamination of the early graft by surviving muscle fibres and allows one to measure the development of contractile properties on a uniform population of regenerating muscle fibres.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/42612/1/18_2005_Article_BF01938500.pd

Review of Available Data for Validation of Nuresim Two-Phase CFD Software Applied to CHF Investigations

The NURESIM Project of the 6th European Framework Program initiated the development of a new-generation common European Standard Software Platform for nuclear reactor simulation. The thermal-hydraulic subproject aims at improving the understanding and the predictive capabilities of the simulation tools for key two-phase flow thermal-hydraulic processes such as the critical heat flux (CHF). As part of a multi-scale analysis of reactor thermal-hydraulics, a two-phase CFD tool is developed to allow zooming on local processes. Current industrial methods for CHF mainly use the sub-channel analysis and empirical CHF correlations based on large scale experiments having the real geometry of a reactor assembly. Two-phase CFD is used here for understanding some boiling flow processes, for helping new fuel assembly design, and for developing better CHF predictions in both PWR and BWR. This paper presents a review of experimental data which can be used for validation of the two-phase CFD application to CHF investigations. The phenomenology of DNB and Dry-Out are detailed identifying all basic flow processes which require a specific modeling in CFD tool. The resulting modeling program of work is given and the current state-of-the-art of the modeling within the NURESIM project is presented

Bacterial Sacroiliitis Probably Induced by Lumbar Epidural Analgesia

Background: Properly administered, lumbar epidural analgesia provides adequate pain relief during labor and delivery, and is considered to be a safe procedure with limited complications. The prevalence of infection after lumbar epidural analgesia is negligible. Introduction: Infection of the sacroiliac joint, although very close to the pucture area, has never been reported as a procedure complication. Case: In this report, we describe a patient who experienced bacterial sacroiliitis a few days after lumbar epidural analgesia for labor. No portal of entry was identified, and we evoked a new potential risk factor that has never been proposed before, namely lumbar epidural analgesia. Conclusion: Sacroiliitis must be considered as a rare but serious complication of lumbar epidural analgesia

Ototoksične tvari na radnom mjestu: kratak uvid u stanje

Ototoxic chemicals can impair the sense of hearing and balance. Lately, efforts have been intensifi ed to compile evidence-based lists of workplace agents with ototoxic properties. This article gives a rough overview of the latest relevant publications, which confirm that toluene, styrene, and lead should receive particular attention as ototoxic substances at the workplace. Moreover, there is sufficient evidence that occupational exposure to trichloroethylene, mercury, carbon monoxide, and carbon disulfide can affect the ear. Based on the existing information, industrial hygienists should make sure that occupational health professionals and the workforce are made aware of the risks posed by ototoxic substances; support their replacement or new technical measures to reduce exposure; make these substances a part of regular screening, develop tools that can early diagnose chemically induced hearing impairment, and investigate further into the ototoxic properties of these substances. Further research should focus on quantifying the combined effects of ototoxic substances and noise.Ototoksične kemikalije mogu narušiti osjetilo sluha i ravnotežu. Nedavno su uloženi dodatni napori u izradu znanstveno utemeljenih popisa tvari koje su prisutne na radnom mjestu, a koje imaju ototoksična svojstva. Ovaj rad daje kratak uvid u najnovije publikacije objavljene na ovu temu. Usporedba navedenih publikacija potvrđuje da bi toluen, stiren i olovo trebalo razmatrati kao izrazito bitne ototoksične tvari koje postoje na radnom mjestu. Nadalje, postoje dovoljni dokazi koji potvrđuju da ototoksične tvari poput trikloretilena, žive, ugljikova monoksida i disulfida u radnom okruženju mogu oštetiti sluh. Temeljem postojećih informacija stručnjaci u području higijene rada trebali bi upozoravati stručnjake u području medicine rada i same radnike na rizike koje ototoksične tvari predstavljaju; poticati ih na zamjenu takvih tvari ili uvođenje novih mjera za smanjenje izlaganja; uključiti ototoksične tvari u redoviti program praćenja i osmisliti mjere za rano otkrivanje oštećenja sluha zbog izloženosti kemijskim tvarima; dodatno istražiti ototoksična svojstva ovih tvari. Buduća istraživanja trebala bi se usredotočiti na izračun ukupnih učinaka ototoksičnih tvari i buke

An improved method for constructing and selectively silanizing double-barreled, neutral liquid-carrier, ion-selective microelectrodes

We describe an improved, efficient and reliable method for the vapour-phase silanization of multi-barreled, ion-selective microelectrodes of which the silanized barrel(s) are to be filled with neutral liquid ion-exchanger (LIX). The technique employs a metal manifold to exclusively and simultaneously deliver dimethyldichlorosilane to only the ion-selective barrels of several multi-barreled microelectrodes. Compared to previously published methods the technique requires fewer procedural steps, less handling of individual microelectrodes, improved reproducibility of silanization of the selected microelectrode barrels and employs standard borosilicate tubing rather than the less-conventional theta-type glass. The electrodes remain stable for up to 3 weeks after the silanization procedure. The efficacy of a double-barreled electrode containing a proton ionophore in the ion-selective barrel is demonstrated in situ in the leaf apoplasm of pea (Pisum) and sunflower (Helianthus). Individual leaves were penetrated to depth of ~150 μm through the abaxial surface. Microelectrode readings remained stable after multiple impalements without the need for a stabilizing PVC matrix

Trends in Occupational Exposure to Styrene in the European Glass Fibre-Reinforced Plastics Industry

Aim: This study presents temporal trends of styrene exposure for workers in the European glass fibre-reinforced plastics (GRP) industry during the period 1966–2002

Potassium Dependent Regulation of Astrocyte Water Permeability Is Mediated by cAMP Signaling

Astrocytes express potassium and water channels to support dynamic regulation of potassium homeostasis. Potassium kinetics can be modulated by aquaporin-4 (AQP4), the essential water channel for astrocyte water permeability regulation. We investigated whether extracellular potassium ([K+]o) can regulate astrocyte water permeability and the mechanisms of such an effect. Studies were performed on rat primary astrocytes and a rat astrocyte cell line transfected with AQP4. We found that 10mM [K+]o caused an immediate, more than 40%, increase in astrocyte water permeability which was sustained in 5min. The water channel AQP4 was a target for this regulation. Potassium induced a significant increase in intracellular cAMP as measured with a FRET based method and with enzyme immunoassay. We found that protein kinase A (PKA) could phosphorylate AQP4 in vitro. Further elevation of [K+]o to 35mM induced a global intracellular calcium response and a transient water permeability increase that was abolished in 5min. When inwardly rectifying potassium (Kir)-channels were blocked, 10mM [K+]o also induced a calcium increase and the water permeability increase no longer persisted. In conclusion, we find that elevation of extracellular potassium regulates AQP4 and astrocyte water permeability via intracellular signaling involving cAMP. A prolonged increase of astrocyte water permeability is Kir-channel dependent and this response can be impeded by intracellular calcium signaling. Our results support the concept of coupling between AQP4 and potassium handling in astrocytes

Competition at silent synapses in reinnervated skeletal muscle

Synaptic connections are made and broken in an activity-dependent manner in diverse regions of the nervous system. However, whether activity is strictly necessary for synapse elimination has not been resolved directly. Here we report that synaptic terminals occupying motor endplates made electrically silent by tetrodotoxin and alpha-bungarotoxin block were frequently displaced by regenerating axons that were also both inactive and synaptically ineffective. Thus, neither evoked nor spontaneous activation of acetylcholine receptors is required for competitive reoccupation of neuromuscular synaptic sites by regenerating motor axons

Regional and hemispheric influences on measured spring peroxyacetyl nitrate (PAN) mixing ratios at the Auchencorth UK EMEP supersite

AbstractThis work presents 15-min averaged measurements of peroxyacetyl nitrate (PAN) obtained during spring 2014 (24/04/2014 – 06/05/2014) at the Auchencorth UK EMEP supersite (southeast Scotland). The aim of this analysis was to investigate the conditions producing the distribution of PAN mixing ratios at the supersite in spring 2014. Air mass back trajectories showed the majority of air masses to have spent substantial time over the UK, continental Europe or Scandinavia prior to arrival at Auchencorth. The median and 95th percentile PAN mixing ratios observed were 0.46ppb and 1.03ppb, respectively. The median mixing ratio was elevated compared with previous PAN measurements during springtime (April–May) in southeast Scotland (corresponding median mixing ratios April–May 1994–1998: 0.1–0.3ppb), which is hypothesised to be due to conditions conducive to regional (European) photochemical PAN production. Additionally, PAN mixing ratios during regionally influenced conditions (0.4–1.5ppb) were substantially more elevated from hemispheric background mixing ratios (0.4–0.6ppb) than for ozone (O3, regional: 10–45ppb, hemispheric: 30–40ppb). PAN and O3 both impact upon vegetation and human health and it is necessary to understand the extent to which hemispheric and regional processes contribute to their abundances in different locations. Regional processes can both increase and decrease PAN and O3 mixing ratios compared to imported hemispheric background mixing ratios. This study concludes that during the measurement period in spring 2014 at the Auchencorth supersite, regional PAN and O3 modifying processes enhanced PAN mixing ratios more than for O3