137 research outputs found
The dynamics of single spike-evoked adenosine release in the cerebellum
The purine adenosine is a potent neuromodulator in the brain, with roles in a number
of diverse physiological and pathological processes. Modulators such as adenosine are difficult
to study as once released they have a diffuse action (which can affect many neurones) and,
unlike classical neurotransmitters, have no inotropic receptors. Thus rapid postsynaptic currents
(PSCs) mediated by adenosine (equivalent to mPSCs) are not available for study. As a result
the mechanisms and properties of adenosine release still remain relatively unclear. We have
studied adenosine release evoked by stimulating the parallel fibres in the cerebellum. Using
adenosine biosensors combined with deconvolution analysis and mathematical modelling, we
have characterised the release dynamics and diffusion of adenosine in unprecedented detail.
By partially blocking K+ channels, we were able to release adenosine in response to a single
stimulus rather than a train of stimuli. This allowed reliable sub-second release of reproducible
quantities of adenosine with stereotypic concentration waveforms that agreed well with predictions
of a mathematical model of purine diffusion. We found no evidence for ATP release
and thus suggest that adenosine is directly released in response to parallel fibre firing and does
not arise from extracellular ATP metabolism. Adenosine release events showed novel short-term
dynamics, including facilitated release with paired stimuli at millisecond stimulation intervals
but depletion-recovery dynamics with paired stimuli delivered over minute time scales. These
results demonstrate rich dynamics for adenosine release that are placed, for the first time, on a
quantitative footing and show strong similarity with vesicular exocytosis
27.9 Efficient Monolithic Perovskite Silicon Tandem Solar Cells on Industry Compatible Bottom Cells
Monolithic perovskite silicon tandem solar cells recently surpass the efficiency of silicon single junction solar cells. Most tandem cells utilize gt;250 amp; 8201; amp; 956;m thick, planarized float zone FZ silicon, which is not compatible with commercial production using lt;200 amp; 8201; amp; 956;m thick Czochralski CZ silicon. The perovskite silicon tandem cells based on industrially relevant 100 amp; 8201; amp; 956;m thick CZ silicon without mechanical planarization are demonstrated. The best power conversion efficiency PCE of 27.9 is only marginally below the 28.2 reference value obtained on the commonly used front side polished FZ Si, which are about three times thicker. With both wafer types showing the same median PCE of 27.8 , the thin CZ Si based devices are preferred for economic reasons. To investigate perspectives for improved current matching and, therefore, further efficiency improvement, optical simulations with planar and textured silicon have been conducted the perovskite s bandgap needs to be increased by amp; 8776;0.02 amp; 8201;eV when reducing the silicon thickness from 280 to 100 amp; 8201; amp; 956;m. The need for bandgap enlargement has a strong impact on future tandem developments ensuring photostable compositions with lossless interfaces at bandgaps around or above 1.7 amp; 8201;e
Teaching About Health Care Disparities in the Clinical Setting
Clinical teachers often observe interactions that may contribute to health care disparities, yet may hesitate to teach about them. A pedagogical model could help faculty structure teaching about health care disparities in the clinical setting, but to our knowledge, none have been adapted for this purpose. In this paper, we adapt an established model, Time-Effective Strategies for Teaching (TEST), to the teaching of health care disparities. We use several case scenarios to illustrate the core components of the model: diagnose the learner, teach rapidly to the learnerâs need, and provide feedback. The TEST model is straightforward, easy to use, and enables the incorporation of teaching about health care disparities into routine clinical teaching
P2X4 receptor function in the nervous system and current breakthroughs in pharmacology
ATP is a well-known extracellular signalling molecule and neurotransmitter known to activate purinergic P2X receptors. Information has been elucidated about the structure and gating of P2X channels following the determination of the crystal structure of P2X4 (zebrafish), however there is still much to discover regarding the role of this receptor in the central nervous system (CNS). In this review we provide an overview of what is known about P2X4 expression in the CNS and discuss evidence for pathophysiological roles in neuroinflammation and neuropathic pain. Recent advances in the development of pharmacological tools including selective antagonists (5-BDBD, PSB-12062, BX430) and positive modulators (ivermectin, avermectins, divalent cations) of P2X4 will be discussed
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International audienc
International Consensus Statement on Rhinology and Allergy: Rhinosinusitis
Background: The 5 years since the publication of the first International Consensus Statement on Allergy and Rhinology: Rhinosinusitis (ICARâRS) has witnessed foundational progress in our understanding and treatment of rhinologic disease. These advances are reflected within the more than 40 new topics covered within the ICARâRSâ2021 as well as updates to the original 140 topics. This executive summary consolidates the evidenceâbased findings of the document. Methods: ICARâRS presents over 180 topics in the forms of evidenceâbased reviews with recommendations (EBRRs), evidenceâbased reviews, and literature reviews. The highest grade structured recommendations of the EBRR sections are summarized in this executive summary. Results: ICARâRSâ2021 covers 22 topics regarding the medical management of RS, which are grade A/B and are presented in the executive summary. Additionally, 4 topics regarding the surgical management of RS are grade A/B and are presented in the executive summary. Finally, a comprehensive evidenceâbased management algorithm is provided. Conclusion: This ICARâRSâ2021 executive summary provides a compilation of the evidenceâbased recommendations for medical and surgical treatment of the most common forms of RS
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