70,074 research outputs found

    Evaluation of the Workplace Environment in the UK, and the Impact on Users’ Levels of Stimulation

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    The purpose of this study is to evaluate a number of recently completed workplaces in the UK. The first aim is to assess the impact of various aspects of the workplace environment on users’ levels of stimulation. The body of previous research undertaken into the workplace environment, identified the aspects to be investigated. Samples of employees from the sixteen businesses were surveyed to determine their perceptions of the workplaces. The results were entered into a regression analysis, and the most significant predictors of perceived stimulation identified. The data also revealed a dramatic reduction in staff arousal levels from mornings to afternoons. Thus, there is a second aim to determine whether changes to significant aspects of the workplace environment during the day can counteract the reduction in users’ stimulation. Two further workplaces were studied to enable changes to be made over a 12-week period. A sample of employees completed questionnaires, and semi-structured interviews revealed the reasons behind the results. It was found that provision of artwork, personal control of temperature and ventilation and regular breaks were the most significant contributions to increasing stimulation after lunch; while user choice of layout, and design and décor of workspaces and break areas, were the most significant aspects at design stage

    Exploring the Production of Extracellular Matrix by Astrocytes in Response to Mimetic Traumatic Brain Injury

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    Following injury to the central nervous system, extracellular modulations are apparent at the site of injury, often resulting in a glial scar. Astrocytes are mechanosensitive cells, which can create a neuroinhibitory extracellular environment in response to injury. The aim for this research was to gain a fundamental understanding of the affects a diffuse traumatic brain injury has on the astrocyte extracellular environment after injury. To accomplish this, a bioreactor culturing astrocytes in 3D constructs delivered 150G decelerations with 20% biaxial strain to mimic a traumatic brain injury. Experiments were designed to compare the potential effects of media type, number of impacts, and impacts with or without strain. Multiple impacts on astrocytes resulted in increased apoptosis, supporting cumulative effects of multiple traumatic brain injury events. Surprisingly, the expression of glial fibrillary acidic protein and S100B by astrocytes was downregulated following injury. With multiple impacts, astrocytes downregulated collagen and glycosaminoglycan expression at acute time points. Suppression of matrix metalloproteinase-2 coupled with unchanging production of transforming growth factor beta-1 and tissue inhibitor of metalloproteinase-1 indicates an inability to degrade damaged ECM or produce new ECM. This was supported by long-term studies which indicate significant decreases in chondroitin sulfate proteoglycan and collagen I accumulation. This could suggest astrocytes experiencing damaging mechanical stimulation enter a survival state ceasing to moderate the extracellular environment at short time points after injury

    Postoperative Pain After The Use Of A Dexamethasone Rinse As An Irrigant Prior To Obturation

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    Purpose: The purpose of this randomized, double-blind pilot study was to determine the effect of dexamethasone on post-operative pain when used as an intracanal rinse prior to obturation. Materials and Methods: Nine adult volunteers consented to enroll. They presented to the Marquette University School of Dentistry Endodontic Department with a diagnosis of irreversible pulpitis. Patients recorded their baseline pain levels on the numering rating scale (NRS). Patients were randomly assigned to either experimental or control group. Patients in the experimental group received 4 mg/mL dexamethasone solution as a final rinse prior to obturation were as patients in the control group received saline as a final rinse. Patients recorded their pain levels at 3, 6, 12, 24, and 48 hours post-operatively. Means and standard deviations were calculated. Treatment effects were analyzed using repeated measures ANOVA. Statistical significance was set at p\u3c.05. Results: Eight patients returned the participation forms. Pain reduction after endodontic treatment was statistically significant (p=0.039). There was no significant difference in post-operative pain between the control and experimental groups (p-0.789). Conclusion: The patient sample size was not large enough to state any conclusions with confidence. However, endodontic treatment remains an effective means of reducing post-operative pain

    Aerospace medicine and biology: A continuing bibliography with indexes (supplement 339)

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    This bibliography lists 105 reports, articles and other documents introduced into the NASA Scientific and Technical Information System during July 1990. Subject coverage includes: aerospace medicine and psychology, life support systems and controlled environments, safety equipment, exobiology and extraterrestrial life, and flight crew behavior and performance

    Organic electrode coatings for next-generation neural interfaces

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    Traditional neuronal interfaces utilize metallic electrodes which in recent years have reached a plateau in terms of the ability to provide safe stimulation at high resolution or rather with high densities of microelectrodes with improved spatial selectivity. To achieve higher resolution it has become clear that reducing the size of electrodes is required to enable higher electrode counts from the implant device. The limitations of interfacing electrodes including low charge injection limits, mechanical mismatch and foreign body response can be addressed through the use of organic electrode coatings which typically provide a softer, more roughened surface to enable both improved charge transfer and lower mechanical mismatch with neural tissue. Coating electrodes with conductive polymers or carbon nanotubes offers a substantial increase in charge transfer area compared to conventional platinum electrodes. These organic conductors provide safe electrical stimulation of tissue while avoiding undesirable chemical reactions and cell damage. However, the mechanical properties of conductive polymers are not ideal, as they are quite brittle. Hydrogel polymers present a versatile coating option for electrodes as they can be chemically modified to provide a soft and conductive scaffold. However, the in vivo chronic inflammatory response of these conductive hydrogels remains unknown. A more recent approach proposes tissue engineering the electrode interface through the use of encapsulated neurons within hydrogel coatings. This approach may provide a method for activating tissue at the cellular scale, however, several technological challenges must be addressed to demonstrate feasibility of this innovative idea. The review focuses on the various organic coatings which have been investigated to improve neural interface electrodes

    Modelling Immunological Memory

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    Accurate immunological models offer the possibility of performing highthroughput experiments in silico that can predict, or at least suggest, in vivo phenomena. In this chapter, we compare various models of immunological memory. We first validate an experimental immunological simulator, developed by the authors, by simulating several theories of immunological memory with known results. We then use the same system to evaluate the predicted effects of a theory of immunological memory. The resulting model has not been explored before in artificial immune systems research, and we compare the simulated in silico output with in vivo measurements. Although the theory appears valid, we suggest that there are a common set of reasons why immunological memory models are a useful support tool; not conclusive in themselves

    Aerospace medicine and biology: A continuing bibliography with indexes, supplement 218, April 1981

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    This bibliography lists 161 reports, articles, and other documents introduced into the NASA scientific and technical information system in March 1981

    Laser-induced generation of singlet oxygen and its role in the cerebrovascular physiology

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    For over 55 years, laser technology has expanded from laboratory research to widespread fields, for example telecommunication and data storage amongst others. Recently application of lasers in biology and medicine presents itself as one of the emerging areas. In this review, we will outline the recent advances in using lasers for the generation of singlet oxygen, traditionally used to kill tumour cells or induce thrombotic stroke model due to damage vascular effects. Over the last two decade, completely new results on cerebrovascular effects of singlet oxygen generated during photodynamic therapy (PDT) have been shown alongside promising applications for delivery of drugs and nanoparticles into the brain for therapy of brain cancer. Furthermore, a "gold key” has been found to overcome the limitations of PDT, such as low light penetration and high toxicity of photosensitizers, by direct generation of singlet oxygen using quantum-dot laser diodes emitting in the near infrared (NIR) spectral range. It is our motivation to highlight these pioneering results in this review, to improve understanding of the biological role of singlet oxygen and to provide new perspectives for improving clinical application of laser based therapy in further research

    Aerospace medicine and biology: A continuing bibliography with indexes, supplement 162, January 1977

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    This bibliography lists 189 reports, articles, and other documents introduced into the NASA scientific and technical information system in December 1976
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